


And Now It's Crystal Clear

by nighttimelights



Category: Undertale (Video Game)
Genre: (no not beasttale sorry friends), ... eyebrow wiggles?, Beauty and the beast trope, Enemies to Friends to Lovers, Gaster Blaster Sans, Soul Magic, aka Beast Sans, okay spoiler tags-, post pacifist universe alterations, time and space shenanigans, tropes galore, yeah the rest of the tags will be added later to avoid spoilers for the moment
Language: English
Status: Completed
Published: 2017-07-16
Updated: 2017-12-27
Packaged: 2018-12-02 20:45:38
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 51,335
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11517135
Author URL: https://archiveofourown.org/users/nighttimelights/pseuds/nighttimelights
Summary: ... or how your sister ended up getting you partnered with the last monster trapped in the Underground.The funny thing about these inclinations of yours is - how likely wouldyoube to fall in love with the monster who spelled out your sealed fate in plain words, and had ripped your sister away from you?





	1. The Bargain

**Author's Note:**

> The first of a 3-chaptered birthday gift to my utter delight of a sister, Joliemariella on both Archive and Tumblr. Go check out her fantastic creators and give her some love.
> 
> This minific will be posted over the course of a day or two, so hang in tight if you're catching it as it goes up - and feel free _(or highly encouraged, really)_ to go send my sister some happy birthday wishes.  <3
> 
> Sis? 
> 
> ... Yeah, don't kill me. X)

 

> **July 20th, 201X**

The snap of twigs and the occasional startled song of a bird in the shifting wind was the only accompaniment to your racing train of thoughts. Any form of proper trail was long behind you now, and you swore under your breath as another spruce branch nearly clipped your face as it slid over the surface of your leather jacket.

Swearing was acting as a liberally-applied balm for the tightness in your chest - but it was having less and less effect the longer you pursued your sister’s trail.

You had gotten home, expecting to see her in her usual place, eyes glued to her screen, some terrible joke or story ready to tell you - but instead you had simply caught sight of her laptop off to one side, still on, and a hastily scribbled “be back in a bit” note left on the counter. Her boots were gone, but her jacket wasn’t, and the clouds outside were darkening. You had deposited your things in their usual places, frowning as you considered your options… she was probably off to that clearing with a view a little ways up the mountain she admitted she sometimes retreated to. She was only ever gone for a couple hours on a normal day when she did head there, something about needing some space to-

Your eyes had caught on her screen then, on the email still opened on it, displaying a message she had received just earlier.

You had barely remembered to lock the door behind you as your leather jacket settled on your shoulders and you flew down the stairs.

… You moved on now to cursing the fact that she had never ended up showing you the clearing. You only knew the minor trail’s offshoot by luck, really, having passed it one day with her during a lull in the conversation. She had mentioned it conversationally, saying that it was about a half hour’s trek up the barely visible path to the best view in town.

The air chilled further as the wind picked up and the sky darkened further above you. There would be no thunder - there almost never was this far north - but you recognized the change in the air pressure all too well.

Your hands snatched at the occasional branch, silently thanking your own inclination for practical boots as you had to scramble for purchase on the ground growing steeper yet. The thought that she had called this a _trail_ almost made you laugh, if it weren’t for the anxious anger and worry choking your chest - granted, she _had_ put air quotes around it at the time, though in the moment you had both just laughed about it. Not for the first time, you fondly questioned your sister’s sanity as you pushed forward, letting yourself get distracted to keep from falling too deep into the rabbit hole of what-ifs as you tried to eye the likely ‘path’ she had followed.

Soon enough, you were rounding the edge of a steep but short cliff, hands passing over branches to keep your hold. You grimaced as you followed the worn line in the patchy underbrush, staying as marginally close to the dense treeline as possible-

Suddenly, the branches were ripped from your hold as an enormous gust of wind buffeted you, sending you unceremoniously over the edge of the cliff.

For the strangest moment, time slowed as your hands outstretched, looking for any hand hold on the mountain side to grab onto, seeing only scraggly grass and weather-rounded edges, and the shredded material of a hoodie horrifyingly familiar to you-

A cut-off curse was all that you were able to get out before you plunged into a crevice in the mountainside below you, swallowed by the darkness.

…

You awoke in an enormous pile of snow.

Despite the unmistakably familiar bite of _too-cold_ that had penetrated your legs, you remained unmoving for a few moments as the disbelief settled in.

Far above you, along the shadowed hint of a cave roof too distant to truly make out, you saw the tiniest glimmer of what might be light.

… You had _fallen_ from there.

_And lived._

… Er. Probably?

At that thought you finally took stock of your surroundings - sure enough, you were in an enormous pile of snow, no hint of the ground below outside of the inevitable firmness of further-compacted snow beneath you. The cold hurt too much for you to be dead, you figured, bemused, and a little worryingly dazed. You were sore, too- did you fall straight on your ass? You must have passed out before you hit the snow, because you have no memory of impact… and you thanked your lucky stars for it, because your body being limp was likely one of the few things that saved you from truer injury.

You’re to the side of a clearing, a steep cliff close to you with the hint of spruce trees poking out from it’s edge high above. Circling the rest of the clearing were… more spruce trees.

You were sensing a theme.

Despite the protest of your aching muscles and the spike of icy pain in every cold inch of your legs and ass, you sat up, blinking away the haze and trying to take further stock of your surroundings.

That’s when you noticed the impact site of compressed snow just a few feet to your side, nearly the size of your own impromptu snow angel.

You also noticed the trail of footprints dragging haphazardly away from it. And just a little beyond that - hardly 30 feet, really - an enormous amount of displaced snow,  footprints and gashes marring the crisp white serenity of the surrounding snow -

And beyond that, what must have been the tracks of your sister ceased. Only the tracks of something far larger, something _monstrous_ , led away from the site, disappearing into the line of the trees.

Your blood chilled further.

Underground.

_You were in the Underground._

And apparently, it wasn’t as deserted as everyone thought it was.

Your muscles forced into action, eking away at the alarmingly-settled cold in them. You pushed and rolled your way out of the snow pile, scrambling to your feet as you were able to get level footing in the deep snow. The tracks were clear so you followed them into the line of the trees, vengeance and furious worry fueling you. Without stopping, you scooped up a recently-snapped branch as you pushed through the forest, the snow retreating to a more manageable height just above your ankles as you entered the cover of the trees.

Monsters had been on the Surface for nearly five years now - this very mountain at the edge of your hometown had been their apparent prison for longer than human memory recalled, and despite the tension and uproar and inevitable rise of outlier human groups (that nevertheless proved so loud as to pretend to be a majority), the monsters had finally gained most civil rights and were largely incorporated into at least nearby society. You had several monster friends yourself, including some coworkers, as well as a handful of truly _best_ friends you and your sister had gotten close to by happenstance and a string of increasingly hilarious misunderstandings when visiting what had become your new favorite coffeeshop, run by a monster who had mercifully set up within walking distance of your apartment.

You shook your head of the memories that were too fond for the current circumstances. As you followed the trail that began to slope upward, absently flexing your hands to stave off the cold, you wondered at the question that always seemed to slip your mind, and anyone else’s, whenever it was nearly brought up - were there monsters left Underground? Shouldn’t… someone check, at least on occasion?

The original hole that the human who helped free the monsters had long since been barricaded and effectively sealed, so it… must have slipped everyone’s minds, the possibility feeling absurd.

… You shook your head again, the thoughts slipping from your mind sluggishly.

Nearly twenty minutes passed in near silence as you made your way along the tracks of whatever it was that must have taken your sister and…

You nearly tripped over a scrap of fabric - the remaining shreds of a hoodie.

You scowled, firmly forbidding yourself from any further guessing as you pushed forward, tucking the fabric into your pocket.

At last, you found yourself crossing a few bridges, now well overhead where you had been originally - and entering the outskirts of a town long abandoned.

… Or, mostly abandoned. While the lights of the houses and shops along the path were off, and the snow had piled up higher than you imagined it would have 5 years ago, there was a noticeable series of trails - all matching the one you had been following, albeit older. The fresh one seemed to follow the way down the town, so you followed it, your pace picking up until you were closer to jogging than actually walking, your stick held at the ready.

At the end of the town, a distinct house loomed -

And wow, did _loom_ fit.

The front of it was certainly a large house by the town’s standards, strung with darkened christmas lights, seeming once-welcoming - but stretching behind it was an enormous addition made of torn and hewn trees to form something looking not unlike a log cabin, but… _enormous_.

Monsters were huge on their own - even the smaller ones often were at a level with humans of at least _average_ height, and monsters of ‘average’ height matched humans of _giant_ stature. Their King and Queen, some of the largest, seemed to push 9 or 10 feet, from what you knew. You had grown more used to it over time, as your town in particular quickly structurally adapted to it’s newest residents as best it could.

This, though…

Your grip tightened on your branch. You didn’t care if the monster was _15_ feet tall, if they took your sister, you had a _goddamn bone to pick with them_.

You pushed towards the cabin in the rear of the house, following the tracks to an enormous door.

Admittedly, you hesitated for just a moment - the door really _was_ at least twice your height, and even still some polite instinct in you had you wanting to knock.

… You didn’t see any windows, though, to peek into…

… Screw it.

You shoulder-checked the door, busting it in and stepping inside with a shout and lifting the branch, ready to swing.

… A little late, your mind flashed in a splitsecond with the possibility that the monster had simply picked up your sister at her collapse in the clearing - but, no, no, surely the disturbed site was _far_ too large and unevenly disturbed for anything but a confrontation-

At that moment, your mind registered the sight before you.

Forget the enormous and haphazard makeshift couch of blankets and pillows to one side, the equally large desk, the towering bookshelves and torn charts and diagrams and sheets lining the walls, the partially uncovered looming mechanical construction in the opposite corner, a red light flashing on several of its panels as it vibrated with a low hum, or the _literal trash tornado_ -

In front of you, right in the middle of the room, stood your sister. She was bruised from her fall, her hair a tangled mess, now lacking her hoodie and only in her tanktop, jeans, and boots, clearly favoring one leg, and her skin still far too pale from the cold permeating the cave.

In front of _her_ stood something taller than the King of monsters himself, tall enough to dwarf your sister, - one of its skeletal clawed hands wrapped around her forearm as if it were as ineffectual as a wooden spoon, and an enormous skeletal tail trailed around them to trap her further, a snarl on the skull of the monster.

The monster’s eyelights snapped up to you, frozen in your position by the door.

His skull was nothing short of dragon-like, two cracked horns jutting out from the crest, and he wore a strangely small and tattered jacket with sleeves that barely went to his elbows, tattered fluff of a collared hood not enough to cover a series of scars trailing down the vertebrae of his neck, down to a ribcage exposed in the open hang of the too-small jacket, slashed with further scarring clear down the chest along ribs that were made of bones that seemed almost plated together. The monster’s legs were like a beast’s - well, a skeletal beast - as if one had risen onto it’s hind legs and grown accustomed to walking that way, despite the talon-like bones of his feet.

Pure, unfiltered magic poured from the monster’s left eye socket, cyan and almost blinding in its light.

“Sis, _run-!_ ”

Your sister’s strained voice snapped you out of the monster’s gaze. Your brow drew downwards immediately, and you opened your mouth to reply, but she cut you off.

“It’s fine, I’ve got this, you’ve just - _you need to get out of here_ -”

 

* **that can be arranged.**

The monster’s voice shook you to your core as your sister cut off her words and shuddered slightly, her expression twisting. You heard it - you know you heard it, low and rough and nearly a growl - but you _felt_ it too, as if your Soul was the true recipient of his words.

“I’m not leaving without her,” you ground out, gaze locking with the monster that held your sister, even if the words were partially directed at her too.

“Listen, he’s just - you don’t have to get wrapped up in this, please, break out of here and I promise, I promise I’ll be fine, just-”

*don’t you know not to make promises you can’t keep?

You felt a different kind of chill run over your skin at the sound and feel of his rough voice once again.

“You’re not convincing me that I should be leaving,” you said. Your eyes didn’t move from his skull, despite his eyelights flickering disapprovingly to your sister.

“Don’t _you_ know that some people goddamn intend to keep their promises, edgelord?” Your sister sassed back up at her captor, tightening the grip of her fist - which was seemed to be balled in the torn fluff of his jacket, though whether to try and pull him more to her level or to push him away, you couldn’t tell.

You fought the urge to both laugh and cry at your sister’s attitude - you could clearly hear the goodwill and friendly teasing behind her words, and knew that her mind was set on trying to appease this… _monster_ , in far more real a sense than you had ever viewed your friends on the Surface - however she had figured it needed to be done.

You spoke slowly, thoroughly noting your odds in a fight with him. “Just - let her go, skeleton… guy, alright? She might have accidentally offended you-”

“Hey- _”_

“-But she means well, okay? She only ever wants to help, no matter _how much shit it gets her into_ -”

“Sis, c’mon, are you _actually_ trying to help me, because I came out to have a good time and honestly I’m-”

“-And I’m not leaving without her. So just… let her go, let’s… talk this out, and no one has to get into a-”

“ _Stick-_ y situation-?”

Your eyes cut at last to your interrupting hellion of a sister, glaring and biting your lip to keep from snorting at the way her eyebrows waggled at you for the pun she interjected and successfully interrupted you with.

*... nah, i think i’ll keep her.

Your eyes snapped back to the monster, finally noting the scars decorating his skull.

*like ya said, she means well, and’ll give me what i need. plus, i’m gonna go out _on a limb_ and say that your negotiation tactics need work.

You realized you were still wielding the sizable branch, and had it in ready position. But with the rest of his words, your willingness to be more careful strained.

“You… you honestly think that you saying you’re not going to let her go is going to make me _back down_ , you sorry excuse for a skeleton?” You took a step forward, hands tightening on your makeshift weapon. “And she’ll _give you what you need_ -?! What - _who the fuck do you think you are?”_

You took another step forward, your posture rising further as fury burned through you. Your sister pulled back towards you as far as she could, but the skeleton monster’s grip tightened on her arm and she winced.

“Sis, don’t-”

“ _Yes I fucking will_ ,” you said, cutting off her words. You saw the lines of red slipping along her forearm through the spaces of his clawed hands, and you grit your teeth. “You know what? No, I _don’t_ care what you want. Every other monster I’ve met has been a goddamn decent individual, each kind and caring in their own ways, _empathetic_ \- but you? You think I’d really just waltz off to leave my own _sister_ in the fucking claws of a kidnapping _asshole_ who thinks it’s funny to joke about his goddamn _coercion?_ I don’t give a shit if she’s okay with helping you, because clearly you don’t give a shit about _her_ , and if you can’t understand why I’m not leaving without her, then clearly you don’t know a _goddamn thing about doing whatever it takes to protect someone you call family-”_

Your body slammed against the wall behind you as the world turned blue.

* **don’t you** **_fucking_ ** **preach to me about family.**

You struggled to breathe under the pressure at your chest as your vision cleared, still tinted blue as the monster spoke, his words slamming against your very soul.

* **you don’t know anything, human.**

Blinking away the last of your daze, you tried to struggle free of his grip - but it wasn’t a physical grip, no - he was stalking towards you, your sister now pressed against his chest, struggling to twist towards you but finding no yield in his hold. He was now fully standing, his tail whipping out behind him, the magic pouring from his eyesocket blazing with renewed intensity. He towered over you, surely hitting at least 12 feet in height, his shadow blocking out the haphazard lighting strung in the room.

* **i’ve sacrificed more for** **_family_ ** **than your** **_fucking_ ** **judging little soul could ever know-!**

He snarled as he leaned in closer, his eyelights nearly pinpricks as you stared back at him, your breath stolen.

He didn’t break your gaze, and you refused to look away, even as deadly certainty of the circumstances settled in you.

A gasp at his chest finally broke the moment, your sister managing to push just enough to turn her head upwards.

“Sans- Sans! Listen to me - please, _please_... it- it’s for your brother, right? You just need to - to run some experiments to try to get to him, and you need a human to help with that, right? I’ll help, I’ll stay, just… let her go, okay?”

Her breaths were short, clearly close to being crushed under his grip, but her voice hardly wavered as she addressed him, halting as her phrasing was.

He didn’t look away from you, but the magic pouring from his eye eased up just lightly, and you found you could breathe once again.

“... Sans, _please_ …”

Another moment passed.

*no.

Her face twisted, but before either of you could speak, you found your breath pushed from you for the split second he needed to continue.

*even if she does leave, if the barrier doesn’t wipe her memory, she’ll try and come back, but… with reinforcements.

You opened your mouth to deny it, a new plan hatching in you, but he cut you off with a narrowing of his eyesockets.

*don’t lie to me. i know what you’d do.

The monster - no, _Sans_ \- shrugged, and you almost felt the words “i’d do it too” in his very gaze. Instead of voicing them, though, he turned from you and walked back towards what appeared to be his workspace.

*so you can help me, and i’ll find someplace… safe… to put her.

He addressed your sister now, clearly.

“What- what do you mean, safe?” She questioned, her voice soft, measured. It was a voice you knew well - one she had used to avert ire when you two faced it before, finding ways to placate while also getting information to genuinely try to help.

Sans’ tail whipped slightly as he glanced at some of his notes hanging on the wall.

*there’s a couple caves further in that’ll do. she won’t be able to get out of there. and yeah, yeah, i’ll bring her food. not gonna starve her or anything.

“But you’ll trap her in a dark cave indefinitely.”

His tail paused for a minute before resuming it’s slow sweep.

*won’t be long if you really help.

You couldn’t speak, still - the pressure holding you above the ground and against the wall was too constricting, but you strained even still as you watched.

Sans finally set your sister down, but kept a firm grip on her arm, only relaxing marginally when she made no move to pull away. You could see her again, now, visible around the side of him as he silently mouthed something he was reading from the notes.

Your heart dropped as you saw something resolute pass over your sister’s expression. Her gaze darted over the notes nearby, the bookshelves - coasting over diagrams she seemed to have been already taking stock of, over charts and finally to the strange machine she now stood close to. Her gaze rested on it for what felt like an eternity in the slow seconds that followed, focusing on a panel of switches, on the chamber that laid open within it-

And then her gaze moved to you. Your eyes narrowed and your brow drew down as you shook your head at her furiously, barely able to shift as you tried to convey every inch of your disagreement with the plan you could already see in her eyes.

After moment, she softly mouthed ‘ _run’_ at you, followed by a small, sad smile, and ‘ _i’m sorry’_.

Sans shuddered slightly, a frown on his skull as he turned slightly to glance back at you.

*could you... maybe calm down from the panic a bit? i said i wouldn’t hurt either of you, and i can feel your soul squirming against my magic, it’s really-

At that moment, your sister yanked her arm from Sans’ slackened grip and darted towards the machine. Despite the flash of pain across her focused expression at whatever was wrong with her leg, she managed to leap over his tail swipe as he reacted quickly, but not quick enough - her hands met the panel she had been eyeing, making deft work of a few switches as she twisted to place a foot in the chamber, one hand on the largest lever as she turned back towards him and reached to snag at his arm-

But he pulled out of her way, lifting a hand sparking with magic towards her to command her soul instead. Before his magic could focus on her, clearly pulling from his hold on you as suddenly the grip on your soul slackened enough for you to breathe, to speak - she slipped, overreaching at his sudden dodge, her wounded leg taking too much weight, and her other hand gripped and tried to anchor her to keep her steady in compensation-

Her other hand was the one on the lever, and with a small _thunk_ , it flipped into the opposite position.

You shouted at the same time as Sans.

“ _No-!”_

 _*_ **_shit-_ **

Reality tore open around your sister as her eyes widened, time rippling and slowing seemingly _around_ her as you were once again slammed back against the wall, Sans’ magic renewing on you as he himself lunged backwards and grabbed onto the wall, his claws burying in the wood. Nothing else in the room was disturbed but for the two of you being _sucked_ towards the tear, towards your sister, and if it wasn’t for whatever magical hold Sans had on you you knew you would be in there too. As it was you could only watch in horror as slowly, too slowly for how the rest of time was flowing, she looked at her hands. Inky blackness was folding around her, pouring and dragging and enveloping her in slow motion, it’s presence draining the color from her as it claimed some terrible hold over her.

Her gaze turned to you, a thousand emotions passing too quickly yet too clearly in her eyes as she opened her mouth - before the blackness surged again, overtaking her. Her focus went to Sans as it swarmed over her, hard and soft and insistent as she spoke, her voice distorting.

“ _Do th… ight… thin-.... belie-... ou-!”_

And the blackness swallowed her and tore apart in the same moment in an explosion of force that blinded your vision in pure white.

You dropped to the ground, knees slamming into the worn wood as you barely managed to catch yourself with your hands. Barely a dazed moment passed before you snapped out of it and surged unsteadily forwards towards the machine, your long-since dropped stick forgotten, your vision clearing just in time for you to trip on your own feet as your energy failed you and your vision threatened to go out again-

You found yourself caught against thick bone instead of meeting the floor personally. With a weak breath you shook yourself, blinking to focus, and realized that Sans’ tail had lifted to catch you. Your eyes went to him, disbelieving, but he didn’t return your gaze. He was on the ground, slumped against the wall with one claw clutching at his chest, his eyelights unwaveringly focused on the machine.

The red flashing lights on it had gone out, and it sat quiet, vibrating and humming eerily no further.

“What… what did you do…” you managed to say, unable to push yourself up to get away from him, or to get towards the machine.

He didn’t answer.

He didn’t even move.

“What… did you _do_ ,” you grit out again, your chest tightening.

*... she turned it on.

His voice was even rougher than it had been. It didn’t even sound as if he were answering you, truthfully - something immeasurable weighted his voice.

*... she _turned it o n ,_ he repeated. Disbelief, now - and… anger?

“What the _fuck does that mean_ ,” you persisted, anger managing to rise to the front of the emotions fueling and draining you.

Finally, his eyelights flashed to you.

*it’s never turned on. it _shouldn’t be able to turn on-_

“It had lights and shit going, what the hell-”

*standby! fucking- she turned the link to - she _activated_ it, and it’s not - i haven’t even been able to _test_ it fully- 

Your knuckles were turning white as you gripped the bones of his tail.

“Are you telling me you were going to experiment on my sister with some fucking _magic bullshit machine that doesn’t even work-”_

For a split second, his expression looked affronted.

*are you- what kind of halfway ethical scientist would- no! Asgore’s beard, i needed - i’m _too fucking big_ , i needed an extra pair of smaller, steady hands, and to observe and test some principles of paradoxic-adjacent tunneling manipulation with a soul less fucked up than mine, particularly with something as strong as a human’s- 

His jaw snapped shut then, as if he realized he had said too much. With a quick flick of his tail he pushed you to your feet, and he stood as well - but you reached the machine before he did.

“What - how do I reverse it? _Where even is she?_ ”

You felt a grip on your soul again despite the fact that you hadn’t touched it, your hands hovering unsure over the machine that had just _swallowed your sister_. You resisted the urge to snarl at the enormous, testy monster who held the very culmination of your being in his magical grasp.

* _don’t touch anything_ , he growled. You narrowed your eyes at him and went to repeat your question, with more _select_ language included, but he cut you off.

*she’s… nowhere, he said slowly. He was… grimacing.

*i… if she did what i think she did… 

His eyelights met your gaze, anger, frustration, and regret in his voice.

*she’s… she doesn’t exist. she… might not _ever_ have existed. 

Your eyes widened. His hold on your soul faltered.

You lunged for him.

Before your fist could meet any part of him, his tail wrapped around you, holding you just out of reach as you ineffectively scrambled to get free.

“ _Like hell she never existed, you son of a-”_

His claws scraped down his face, clacking as a sound close to a groan escaped him.

*just- stop attacking me, okay lady? listen, she just activated an _incomplete machine_ that, at its basis, was _meant to tear through the boundaries of space and time_ . 

You stilled finally, your eyes still narrowed, your grip tight on his tail.

“Why-”

*i’ve got my own damn reasons, he snapped. Suddenly you remembered what your sister had said earlier-

_“it- it’s for your brother, right? You just need to - to run some experiments to try to get to him, and you need a human to help with that, right?”_

You breathed out. “Your brother…”

He tensed, his eyelights narrowing.

*... in any case. point is- _the machine isn’t finished._ i’ve got it… far, but it’s never truly been turned on. partially because i knew it wasn’t stable or ready, partially because even if it was - it didn’t have the power it needed to truly _create_ that rift, or even to turn on fully in the first place. 

“... and somehow, she turned it on anyways.”

The groan was clearer this time.

*it must have had something to do with… with her soul? maybe she was really determined - but that’s not her trait, so it shouldn’t have been enough… but if not that, then what could have- _fuck_ , he cut himself off, swearing vehemently. *there’s too many variables! this is why i needed to experiment, but she had to go and-

“Don’t fucking blame her, you dick!” You interrupted, glaring at him and kicking at his tail ineffectually. “You’re the one - if you hadn’t _trapped_ us here, she wouldn’t have tried to pull some shit to get us free-!”

*she fucking agreed to help me, before you bust in! He shot back, pulling you slightly closer.  *i found her about to die of hypothermia in the Lower Levels - which by the way, _who the fuck wears just a tanktop to a mountain_ \- and when she woke up with me over her - okay, yeah, she freaked out, but in the end she said she’d hear me out if i could “actually” keep her from dying, he said, adding air quotes and an… almost _fond_ roll of his eyes as he remembered some passing piece of their interaction.

… That fondness _pissed you off_.

“What, so you saved her so you could get her to help with your mad scientist bullshit _under duress_?”

He bristled at that. *i wasn’t going to let her die either way, but i wasn’t going to say no to a literal goddamn miracle falling from above and giving me the damn help i’ve needed this whole time-!

“But you still wouldn’t have brought her back to the Surface-”

*i wasn’t lying about what i said about the barrier, lady, he said harshly. You stilled once again in his careful but unrelenting hold as you waited for him to continue a pit growing stronger deep within you. His eyelights slanted off to the side, unfocusing slightly. *you really might lose your memory if you pass through - and i don’t know if it’d be just of being here, or of _everything_ . and even more importantly, you had to have passed through the barrier when you fell in here. even if it didn’t alter _your_ memory…

Your wandering thought from earlier returned, full force.

Nobody from the Surface thought about what might be still in the Underground.

Every time you did, or tried to, the thoughts just… slipped away.

“... You keep saying the barrier. It’s… a new one? One that-” you breathed in sharply. “It makes people forget you exist?”

Sans’ expression was grim.

*essentially, yes. 

He looked back to you, finally.

*nobody remembers i exist any longer. they literally _can’t_ . and you…? He looked grim.  *they might not remember you, even now… or more likely, they won’t be able to think or wonder about what happened to you. it’d be like a distant memory of someone having passed on. you know they existed, and you can probably remember various things you did with them, and feelings you had, and you’ll know they’re not around… but you won’t be able to dwell on it. you just… move on, without a second thought.

For the first time since entering this cabin, you didn’t know what to say.

Your eyes went back to the machine, finally.

Sans’ tail unwound from around you, tentatively, but you didn’t make a move.

*... she… i’ve seen something similar happen, only once. she... you didn’t turn around to look at him, but you could hear him seem to pause to try and find the right word for it. *she’s… been scattered across space and time. there’s... any anchor she had to this timeline - er, to reality - is gone. i don’t… theoretically, she still exists, just… not within any reality.

You simply stared at the machine.

For a time, the only sound in the room was the quiet rustling of the strange, contained tornado in another part of the room.

Then, so quickly that you saw him startle, you whirled on your feet and stared up at Sans, your gaze resolute and your hands on your hips.

“Okay, what do I do?”

*... er. what? 

You gestured back at the machine.

“Whatever it was - whatever it was she was going to do for you, tell me what it is. You’re a science guru or something, right? Well let’s get to it. She’s not getting any closer to home while we stare at the damn thing.”

The look on Sans face spoke volumes of his opinion of your sanity.

You scoffed at him, but your gaze shifted to stare hard at the machine. “... There’s no ‘if’ here. It’s not a ‘try’ to get her back. I’m going to drag her back into this universe _personally_ punching some eldritch terror in its many-eyed terror of a face if it comes to it.” Absently, your hands went to your pockets - and in one, your hand found the shred of material from her hoodie you found earlier. Your voice strained as you continued, your hand shifting to clench the material. “She was only trying to… to do right. Taking a - a shitty risk, just to try to save-”

Your mouth snapped shut. After a moment you took a deep breath, willing the painful prickling at your eyes to get under control before your gaze went back to Sans.

“... Think what you want of me, whatever. I came here to get her back. That got… a lot more complicated than I ever could’ve guessed, and I’m not exactly psyched to be basically stuck here in some forgotten purgatory cursed-land scenario, or working with the edgiest scientist this side of sci-fi - _or that_ _my sister got smeared across time and space by the same damn scientist’s half-assed creation_ -” you jabbed a finger towards him, a brow lifting. “-but I’m sure as hell not going to let this stand. So whatever we need to do - let’s do it.”

The ridges above Sans’ eyesockets that seemed to form some sort of browbone lifted at your declaration.

*... you really think that insulting me and ordering me about is going to make me want to help you? 

You crossed your arms, your brow only lifting further. “You needed her - or whoever, apparently - to help you do the work for that machine anyways, right?” He didn’t deny it, and you found a smirk slipping into your expression. “That’s what I thought. Look, it’s two birds, one stone, isn’t it-? Whatever you need the machine for - something to do with your brother, who I’m guessing may be in the same eldritch-inspired boat as my sister - _you_ need help to get it done, and _I_ need the machine running to get my sister back.”

Sans’ eyesockets narrowed. You didn’t break your gaze from him, waiting it out without wavering, fiercely ignored the hot pressure building in your chest.

Finally, he huffed.

*yeah, alright, you make a good point. His own browbone lifted then, and a smirk spread on his skull. *you’re going to have to bite back some of the sass though, lady - this work’s a hell of a lot more delicate than you could ever even begin to think. if i tell you to do something, _you have to do it_.

You scowled. “... Within reason.”

*not sure how good a judge ya are of that, lady. 

The canny twist to his smirk that flashed across his dragon-esque skull rose something fiery in you, and after just a moment, you muttered your name. His brow quirked upwards.

“... That’s my name,” you added, your gaze slanting off to the side.

A strange rumble echoed from him for a moment.

*yeah, alright. the name’s Sans, _sparky_ . 

“Sparky?” You felt yourself color as indignation and embarrassment flared in you and your arms uncrossed at last.

*what? i mean, with that attitude - oh, or maybe it’s that you’d prefer something else, _sweetheart_ ? 

“ _Oh my god_.”

*like i said, it’s Sans, but if you insist… 

“I’m in hell. I fell through a hole in the ground, and I landed in hell.”

*you must’ve placed a shitty bet last time you went out, since it looks like _hell froze over_ . 

You groaned and buried your face in your hands, clenching them to resist the urge to take a whack at the monster you needed at least _mildly_ amenable to working with you.

… You also had the smallest hint of a smile tugging at your lips.

*you’re smiling, aren’t you? 

He sounded smug.

“Shut up.”


	2. The Scientific Process

**Notes for the Chapter:**

> (wellp, turned into 4 chapters thanks to a sleepless night and a number of added scenes, so i hope you enjoy this second part of now 4!)
> 
> (also, apologies for the slight switch in formatting for Sans' text - the coding was being a nightmare, so for time reasons i settled for just having his text bolded. i'll update appropriately later when i can.)
> 
> (and again - Happy Birthday, sis, i'm delighted that we both laughed until we couldn't breathe at the fact that i effectively fridged myself for plot development.)

> **July 23, 201X**

***so i’m guessing interdimensional quantum physics and magical theory isn’t your normal bag up on the surface, huh, sweetheart.**

“I swear, I will pour tree sap all over your favorite pillow.”

Your indignant threats only pulled a chuckle out of Sans, lounging across the room from you in his weird pile of blankets and pillows. An old notebook floated in front of him, born on his own magic, bursting with notes and with pages that had been aged and worn and too often opened.

***i’d like to see you try.**

You grumbled from your staked corner, blocked off by a few wooden box crates you had dug up over the past few days, surrounding with your own stolen blankets - er, well, _borrowed_.

It’s not like anyone else was down here to use them.

You only had the one pillow to add to your nest of blankets - begrudgingly gifted to you by Sans after your first night was spent tossing and ineffectually attempting to bundle up a blanket into a usable pillow.

Papers surrounded you, your own scrawled writing decorating fresh pages as you took notes based off of the books surrounding you. Sans hadn’t let you near _his_ notebooks yet, citing that before he could consider letting you near his apparently literally irreplaceable work, you’d have to prove that you knew enough to not blow the timeline to pieces.

“I’ll blow _your_ timeline to pieces,” you had muttered. He had simply snorted, and _you_ had ended up with your papers ‘accidentally’ blown into the trash tornado for your troubles. It had taken you nearly 45 minutes to snatch them all back.

With little else to distract yourself with, you had more or less thrown your efforts into at least trying to get a better grip on this quantum nonsense outside of the cursory understanding you had thanks to scattered Discovery channel specials.

***quantum may imply a lot of things, but i’ll give you a heads up - the chances of my skull bursting into fire from the force of your gaze alone is pretty low on the list of universal probabilities.**

You hadn’t even realized you had taken to glaring at him again.

“Maybe it’ll make this stupid headache feel a little less worse, though,” you said. Your fingers went to your temples as you let your head hang, your gaze flitting over the latest book Sans had tossed at you - _Quantum for Dummies_.

Ha, ha, _ha._

***doubtful, sweetheart.**

You rolled your eyes and thumbed to the index section of the book with a grunt.

“Let up on the _petnames_ , asshole.”

***whatever you say, sweetheart.**

\------------------------------------------------------

> **August 4, 201X**

Two weeks, you had been here.

Two weeks, studying bullshit reality-warping science, relearning basic mathematical terms you had barely thought about in years, gaining headache after headache, eating almost nothing but old packaged ramen you had to prepare yourself and weird but mercifully crispy potato ‘chisps’.

Two weeks, and _the asshole still hadn’t fixed his water heater._

You shuddered your way through your post-shower routine as quickly as you could, desperate to get your clothes back on. You had by now scraped together at least two changes of clothes, thanks to some slightly guilt-plagued digging through the local buildings, so at least you had something to change into… even if it wasn’t _fresh_ , since it took an absurd amount of time to dry anything by hanging like you were forced to, especially considering you had to wash your clothes by hand, so you sure as hell weren’t going to spend excessively frivolous time on the matter. The only thing you never removed, even in your quick showers, was the thick and tightly woven bracelet on your left wrist - crafted carefully from all that remained of the hoodie scraps you had saved that first day.

You strode quickly through the dark house - which was considerably cooler than the cabin, since it’s ‘heat’ really only came from the shared wall with the cabin.

Sans never entered the house - considering his size, it was impractical and nigh impossible without significant structural damage, but you couldn’t help but wonder why the hell he lived off the back side of _this_ house anyways. The rest of it was empty - almost totally cleaned out of remaining items, so you couldn’t gleam anything about the original residents.

You looped outside in a dash, holding your breath against the temperature drop before you snapped the cabin door shut behind you.

***bit nippy out, huh?**

Sans’ lazy drawl caused you to roll your eyes - a habit that was only growing.

“Hell of a lot more than it needed to be, considering you still won’t _fix your water heater_ ,” you bit out as you kicked off your boots, crossing to your claimed corner and burying yourself under the blankets as quickly as possible.

 ***well, since you’re warmer, isn’t it better? less of a temperature difference to when you have to walk outside,** he said, not glancing over at you. That one old notebook hovered in front of him again, as it seemed to so often do.

“That is so beyond not how that works, it’s insulting.”

***sorry, can’t hear you, you’re trapped in some sort of blanket dimension.**

You snorted - then flushed for an annoyed moment, relieved that the sound was muffled so thoroughly by your mountain of blankets.

“... seriously though, can you fix the water heater? It’s bad enough being stuck in here all the time, I don’t think it’s too unreasonable to not want to freeze every time I take a shower…”

Sans grumbled something unintelligible. You stuck your head further out of the blankets without thinking.

“What was that?”

***... sure must suck being stuck somewhere for a few weeks, wow. yeah, wonder what that’s like.**

Sans still wasn’t looking at you, his notebook floating a little more squarely in front of his skull. Several pages of added notes surrounded the notebook, obscuring his expression.

… well, shit.

You frowned, looking away. Asshole he certainly was, but… well, he was clearly stuck down here, _alone_ , for… at least 5 years.

“... Sorry,” you mumbled.

He was quiet for a few moments, then shrugged.

***s’whatever.**

“No, no,” you groaned, rolling over till you were largely obscured from easy sight behind your box crates to tighten yourself in the hold of your blankets. “I’m annoyed, but that was still shitty of me to say.”

There was a disbelieving huff from Sans, and the sound of the bones of his tail shifting along the floor.

 ***you’re apologizing to the** **_asshole_ ** **?**

His tone was dry, and you could almost see the cynical look on his skull - one you were getting pretty familiar with.

“Takes one to know one, looks like,” you said lightly.

He laughed. The sound was half-startled, half-choked, as if that was the last thing he expected you to say. It quieted quickly, turning into a drier chuckle in recovery.

***you said it, not me.**

You rolled your eyes, even though he couldn’t see it. Still, there was the faintest grin on your face.

A couple days later, when you dashed back into the cabin and all but dove into your blanket-bed, you found a bowl of ramen sitting on one of your box crates. It was hot, and had just finished cooking.

Sans was asleep, taking one of his frequent naps, so for once when the smile started pulling at your lips, you didn’t fight it.

\------------------------------------------------------

> **August 9, 201X**

***... you’re getting bark all over your blankets.**

“Since when do you care about a mess?”

***hey, i can care about a mess when the fancy strikes.**

You pointed to the trash tornado, making its slow and unpredictable way about the room, not looking up from the branch the rough size of a large walking stick held vertically in your lap.

 ***... picking up is a** **_breeze_ ** **if you put your mind to it.**

You snorted, barely tossing him a glare. He lounged in his pillow and blanket pile, a bag of popato chisps caught in the plating of his ribs from earlier, a few notebooks suspended in the air in front of him, a quantum physics book flipping pages next to that, and a number of balled up note papers scattered about him.

 ***what? didn’t say** **_i_ ** **had the mind for it, sweetheart.**

The grin in his tone was infectious, but you fought the urge and instead continued focusing on removing the remaining shreds of bark from the branch you had brought with you that first day a couple weeks ago. It’s needles had been almost-carefully-enough removed and gathered in a bowl you commandeered - it still smelled nice, after all - and the stray wimpier twigs had been discarded too. It was smoothing out, but it was definitely no quick process.

“What, so _I’m_ supposed to?” You groused. Your words had been losing a bit of their bite the past few days, but he had thrown enough migraine-inducing theoretical science and magic books in your direction each day that they still weren’t exactly _friendly_.

You saw Sans’ form shift in a shrug.

***it’d be a little sad if a tornado was better at cleaning than the only two sentient beings in the entire Underground.**

“Thing’s gonna _become_ sentient if it consumes any more of your old food.”

***excuse you, that food would outlast either of us and you know it.**

“Y’know, with the sodium content of the apparent _only_ goddamn food groups of ramen and chips you’ve got here, you’re probably not wrong there.”

 ***i’m sensing you’re getting somehow** **_saltier_ ** **.**

“Don’t be jealous. You wish you could achieve this level of salt.”

 ***not with the way it’s bogging down your reaction time. what is this, hour three of stick peeling? there’s quantum to be studied and simultaneously not studied. priorities,** **_sweetheart_ ** **.**

“I needed to stare at something that made me feel _more_ intelligent than a hunk of wood, not less,” you said. “Schrödinger can go exist-not exist in a box for a bit. Though if you want me to get done faster, you could tell me where the hell you hid all the knives in town so I could carve it down properly.”

 ***i’ll let that comment lie** **_unboxed_ ** **, but you’re more on the wavelength of Heisenberg and uncertainty if you think i’m ever giving that one up.**

“That doesn’t even _make sense_ ,” you groaned. “Heisenberg’s principle wasn’t - okay, yes, _uncertainty principle_ , you ass, but I’ve had my eyes crossed over at least two dozen extrapolations of how the hell that applies and he just - that doesn’t - _I’m pretty sure you’re full of shit_ ,” you said, feeling more certain than your headache or the still seemingly nonsensical jumble of deeper dives into dimensional and quantum theories. You caught sight of his smirk spreading, and instead of seeing that, decided to let your forehead thunk against your stick.

… That ended up being a mistake. You made a noise as you pulled away, tree sap sticking to your skin.

 ***ooo, impressive.** **_double_ ** **the** **_sticky_ ** **situation you’ve got there now.**

“I change my mind. You’re the one I want to shove into a box.”

\------------------------------------------------------

> **August 17, 201X**

“... Okay, I admit, so far this is on par with the water heater working this morning.”

***glad to hear otherworldly crystals, glowing water, and plants nearly the size of you that can echo back anything they hear at a simple touch rises to a level on par with 5 minutes of hot water.**

“Hot _running_ water.”

Your easy jibe was a lot softer in tone than you would have tried to have it, but frankly, you _were_ floored at your surroundings.

Waterfall was the most beautiful place you had ever seen.

Your boots mercifully wicked off the damp of the ground underfoot, but you had long since tied your jacket around your waist for the warmer atmosphere of this portion of the Underground. Your eyes flit across every surface, your gait slow, but for once Sans wasn’t ignoring your pace and moving at his own.

… Then again, this was the first time he was letting you out of the general area of Snowdin.

“... Why the hell don’t you live _here_ ?” you whispered. Echo flowers - you had seen one aboveground, but they were still being coaxed to adapt to the new environments, and so they weren’t widespread by any means, or even really available for much public viewing, but luckily one of your dear monster friends happened to be one of the ones keeping an eye on that project - stars, echo flowers were _stunning_. They creeped you out, just a little, and you couldn’t help but be incredibly curious as to how they worked.

Sans remained quiet, his tail shifting silently as you approached one and gently touched one of its petals, prompting it to echo - but rather than words, quickly fading, delighted laughter came from it, as if someone had run past at just the right moment and way to catch a moment of pure joy in this flower’s magical core.

Still, he shot you a look as you stood up and walked onwards, his gait lazier than usual to allow you to not have to nearly jog to keep up with him - or, in this case, for him to keep halting to wait for you to catch up.

***water galore and countless basically-irreplaceable notes and machinery doesn’t generally mix, no matter how deep underground you go.**

You opened your mouth to retort at his dryness, but… well, that was fair. You trekked onwards through the winding caves, leaving the Echo Flowers behind and twisting along sweet and melancholy-lit stone paths surrounded by water in relative silence. The change in scenery from the snowscape you’d grown accustomed to was so welcome it was still staggering you, nearly an hour into your walk.

“Still,” you said so much later, your mind drifting again to the aura of Waterfall as a whole, letting yourself pretend that was an argument. “... Magic, or something.”

Sans didn’t seem to have any issue catching onto your trailed thought.

***i’m more concerned than ever if after reading all those papers you think that magic is an automatic and permanent laws-of-the-known-world breaker at the basic level of ‘water makes shit wet’.**

“It’s a hard belief to break,” you replied, shrugging, a rueful grin slipping onto your expression. “You grow up with all these movies placing pretty minimal - or at least weirdly weak - laws on the miracles ‘magic’ can work, it takes a lot to unseat that and find out that magic’s actually got… _actual_ rules.”

Your words ended with your tone twisting as if personally offended, and even with him looming over twice your height, you caught the slight chuff of a snort from Sans.

 ***sorry you got played in the classic** **_bait and ‘witch_ ** **, sweetheart. reality sucks, doesn’t it?**

“Boo, try-hard. 1 out of 10. Would not recommend, you _literal giant walking skeleton dragon._ ”

 ***’** **_wing_ ** **and a miss, considering i’m lacking some quintessential dragon parts. better luck next time.**

“Okay, a really sad dragon then. Hope you’re stocked up on tissues, asshole.”

***you wound me, sweetheart, truly.**

Your boots scuffed against wooden boards as you huffed a laugh despite yourself. The path had trailed and shifted to a board walk, the water… a little too far to see below, in the dark light. And there were no railings. You decided not to comment, considering the common theme you were finding in the lack of safety features in the Underground, but you still found yourself taking a step closer to Sans’ side. He didn’t comment on it as he lead you down what was proving to be a maze of path options.

“That’s what you get for throwing a notebook full of equations at me with notes only in some weird fucking hieroglyphs this morning. Get read, jerk.”

***you’re the one that started drooling on my old notebook. next time flop your weird squishy, drool-y human body backwards when you take an impromptu nap, not forwards onto my stuff.**

“You call _everything_ your stuff, you snoring asshole. How can you even snore so loud? You don’t even have - well, _literally any_ of the needed parts.”

***you wanna know my secret?**

He was leaning in now, and you caught the shift of his tail to wrap around to your other side, untouching, but becoming familiar in its habit of scooping in like that when he had something on his mind that never seemed to fail to get a rise out of you.

“... Do I?” You asked drily.

His grin sharpened, his fangs catching the low light of the cavern.

 ***** **_i don’t snore_ ** **.**

Your brow furrowed as you came to a stop. “You don’t - what do you mean, I’ve heard you-” Your eyes widened then, your mouth falling into an ‘o’. He stood straighter again, his eyelights wicked in their sockets. “You - _you’re not goddamn asleep when you’re snoring, you’re making that sound on purpose-!”_

He bust out into laughter as realization and horror and pissed-off righteous fury crossed your expression in quick succession. The sound was rumbling and deep, hitting you right in your core in the doubly-felt way his voice always did, filling your chest in a way that you decidedly _did not_ welcome right now, no way, no thank you, you were going to be mad-

You aimed a well placed slap as high as you could reach - which, of course, was only his upper arm, even with his posture not fully straightened up. He didn’t even dodge it, and you swore under your breath at the sting of the contact. His old, small jack provided little padding, and you swung a little too hard.

His laughter died down at last, and you tried to not dwell on the fact that that was the first time you had really heard him laugh. Instead you turned your face away, grumbling indistinctly as he got a hold of himself in his own sweet time. You finally took in the fact that the boardwalk, despite having widened, came to a dead end.

“Yeah, alright, _comic Sans_ . Where next? Is this some magically-triggered puzzle thing we need to do to get across?” You sighed. While out hunting for clothes and stretching your legs on the rare occasion, you had to navigate more than your fair share of inexplicably still-functioning puzzles - ones that _apparently_ could self-reset in even more difficult and annoying manners, something that Sans had offered only a shrug and an amused turn of his back when asked about.

Sans’ snickering faded finally as he regarded you with that same too-pleased prankster look and his eyes. Not a harmless kid prankster either, no - you full-well meant a primordial trickster _god_ , one that would just as well see you accidentally killed for a misstep in some trick or puzzle or bet.

“... Okay, yeah, I’m going to repeat my growing theory about all monsters being ancient deadly tricksters at heart if you keep looking at me like that. Or, I dunno, maybe you’re all just the equivalent of when superhumans in movies or comics don’t understand how breakable their human acquaintances are.” You eyed him warily, starting to lean away, remembering a particularly _athletic_ jape one of your monster friends had enacted on you and your sister one time...

***nah, no magic needed for this one.**

He shrugged, innocence crossing his face too drily to be believed.

“... Okayyy, what’s it take, then?”

His grin returned full force, and too late you tried to take a step back. Before you could turn to book it, he had scooped you up and stepped towards the chasm below the boardwalk.

 ***just good ol’ gravity,** **_sweetheart_ ** **.**

And with that, he stepped off the edge of the boardwalk, the wicked glint to his eyelights spreading to twist his grin as an unadulterated shriek was ripped from you.

You clung to him, your arms immediately circling his neck despite yourself, your imminent death aggressively not accepted but _wholeheartedly acknowledged_ as seconds passed in the roar of misplaced air around your forms-

Blue flared around you as fully as the water that splashed like a cannonball’s waves as Sans’ clawed and beast-bent legs met the water below, finding steady purchase to no logical explanation, his descent and by proxy yours slowed just enough to not give you a concussion from the sudden deceleration.

Your scream cut off with a _whumpf_ of the air leaving you, and in an unceremonious wave and splutter of dark water.

You didn’t move for a moment, adrenaline pumping through you, your lack of meeting a more reaper-inclined skeletal guide registering.

Even as you found your breath, you couldn’t find the strength of mind to consider taking a swing at Sans.

***did i leave you breathless?**

Your gaze slowly met Sans’. That smug look was back, colored just slightly by whatever his own form of adrenaline was. He looked far more alert than he ever did, something you might have actually noted with some appreciation if not for the fact that it seemed to come at the cost of your own sanity.

“Fuck off,” you said simply.

He strode forward, the water sloshing around his bones and tail as he moved towards a patch of golden flowers that peeked over the surface of the water. Setting you down, he moved to make his way forward again, tossing an unapologetic look back at you as he did so.

***sure, but have fun getting back on your own. and without even appreciating what’s around you - damn.**

At that, you finally took in your surroundings - yes, more Waterfall, though considerably darker than other portions of it, lacking as it was the glow - but instead it was… it was filled with _stuff_ . Piles and hills of unglamorously beautiful _stuff_.

You sucked in a breath as you caught sight of a t-shirt in a pile, not far off from what looked suspiciously like a miraculously sealed box of detergent. Broken electronics abounded, and you had a feeling the decidedly unsavory smell in the air denoted some less favorable items buried in the junk, but the site of coolers and sundry unopened boxes had you striding quickly into the water after Sans, paying little mind to the water sloshing up to your knees - you were soaked as is.

“Holy shit, what a _dump_ ,” you said.

Your tone was nothing short of reverent.

There were so few supplies to speak of back in Snowdin - but this…?

You heard a chuckle off to your side where your hands hovered uncertainly over the pile, nervous to carelessly dig in, but too excited to quite handle thinking clearly on the matter.

***funny how your standards change, isn’t it?**

You felt something smack against your shoulder, and reflexively you snatched hold of it before it fell into the water.

Twisting to get better light on it, you realized what you held - a pair of worn but sturdy work gloves.

***can’t say i need ‘em.**

Your gaze lifted to Sans, but he was already sifting methodically through a different pile, an old canvas bag hung off the end of his tail as he considered different machinic parts.

***keep an eye out for the wires i mentioned the other day, would ya? gonna need some spares.**

A moment passed quietly. You pulled the gloves on - nearly a perfect fit, and long enough to cover up your bracelet, too. You turned back to your own chosen pile, taking stock of how the items were laid.

“Will do.”

\------------------------------------------------------

> **August 20, 201X**

“Okay, so then, the implications of the stress of the observation itself on the phenomenon would… but the link between the magical effect as a wave as opposed to a particle in the given circumstance means…”

You tapped out the vague beat of your thoughts as you muttered broken pieces of your musing on the problems posed by the latest notebook you had gotten access to at Sans’… well, at his aim, to be honest, considering the monster seemed unaware of the means to simply _pass_ someone a book rather than lobbing it with frustrating accuracy at a person right when they happened to doze off.

The month had passed in such strange bursts of time, and at this point you were so used to the relative close quarters of the cabin - while wide and long, the single-room space was considerably more oddly and notably used when the approximations to furniture all suited a 12+ foot tall skeleton beast - that you were able to better ignore Sans’ occasional staring… like he was doing right now.

He never provided reasoning when you had ‘caught’ him previously - but he also often didn’t bother to stop even when you _did_ notice, so there was less and less of a point to even putting in the effort to give him a bad time about it.

Your train of thoughts on the latest theories _were_ interrupted by his voice, however.

***hey, c’mere for a second.**

That got your attention - he almost never actually _asked_ for your presence, and certainly never while he was working at his workbench.

So you marked your page and set down the notebook carefully, a fairly deep respect for his personal notes at this point. As much as the monster could rub you the wrong way, after seeing even as much of his notes as he _did_ share with you, you’d be an outright liar to call him anything but a mind at a level of genius in these fields.

He sat on the floor to fit at his workbench comfortably, so your shoulder was just above the level of his own when you approached to stand at his side. An array of parts rested on the workbench, maddeningly but apparently in _some_ logical way laid out, covering various blueprints and framed by various notes. Your expression was openly curious, though a brow lifted as you checked Sans’ expression, confused.

His claws deftly picked up a tight bundle of cords, horrifyingly tangled, and small even by the standards of your own size.

***untangle that for me, would ya?**

Your brows lifted further.

He hadn’t asked for help - or even heard out your demands for something, _anything_ practical and productive to work with - this whole time.

For that reason, you simply nodded at the request for such a seemingly minor menial task, turning your attention to the barely-tinted wires gripping each other in their unintentional weave.

… As it turned out, he had three more boxes of fine wires similarly tangled.

You almost screamed, if not for the abject relief at a variation in focus still tinting your mood. The notebook laid by your blanket nest, and for the first time, you had no time to open it again until the next morning.

\------------------------------------------------------

> **September 3, 201X**

“... So I don’t suppose the trash tornado is _supposed_ to self-replicate.”

***...i’m more of a chaotic neutral than a chaotic evil.**

“Can you chaotic good it into cutting that shit out?”

 ***if it was more magic than the product of a couple years of developmental science, it’d be a** **_breeze_ ** **.**

Your hands dragged down your face as you watched a dozen tornadoes of varying size pass around every blanket, paper, and book in the room. Your stick occasionally whipped dangerously around, never tangling for long enough in a blanket. The distressing crunch of popato chisp bags could occasionally be heard over the rush of disturbed air.

“How long is this going to take to fix?”

Sans didn’t say anything, his eyelights set on the havoc being wreaked in his cabin. Not a single book or paper laid untouched by the winds, all born and twisted in the mini cyclones.

You groaned.

“I hate it when you manage to give me more information by keeping your dumb jaw shut than when you open it. I don’t… I don’t even entirely _want_ to know what happened.”

You watched as your jacket was passed along a few different tornadoes directly in the center. They were deceptively strong - it was only Sans’ quick reaction and magic that hauled you back earlier when you tried to dart between them after you returned from your shower only to find your personal notebook suddenly torn from its resting place in your nook. The tornadoes had since further multiplied, contained only in the barest sense of the term and in the fact that despite their apparent power, they hadn’t ripped apart the cabin.

“Can’t even eat the shitty food that’s gonna give me a thousand different kinds of heart issues,” you mumbled, watching hopelessly as your most recent box of ramen was upended at last, scattering packets of sad dried noodles to the further corners of the room.

***... yeah. y’know what? fuck this.**

You turned to look up at Sans with a brow raised, but met a faceful of fabric instead. You spluttered briefly as you tugged it off you and took stock of it - a worn, slightly torn, but nevertheless thick and fluffy blue jacket…

Your gaze flashed upwards.

Sans stood with a completely and utterly _done_ look on his face as he glared at the aftermath of his own creation, his ribcage and upper arms completely bare. The scarring you had become familiar with stretched along the newly revealed areas of his body, most older in appearance, but many seeming recent enough in how little they were worn down and how still more starkly-different the coloring was of the bone in the area.

His gaze turned back to you then, a brow ridge lifting.

***you gonna wait for a tornado to take that?**

“... what?”

Hu huffed and jerked his head towards the door.

***c’mon, yours is a lost cause for the moment. put that on, we’re going to get dinner.**

A few more stupefied glances between Sans and his coat and you finally slipped it on, unable to help yourself from burrowing into the fluff of his hood, even worn as it was. It really was _warm_ , though you had no idea how the warmth lingered considering the jacket’s owner was simply bones. It smelled incredibly largely of pine to no surprise, but with a faint hint of something… tangy? Alongside the warmer hints of campfire and old books.

You shook yourself with a slight heat to your cheeks as his skull turned back towards you from his position already through the open doorway, quickly striding off after him before your sudden flustered daze left him with any further joke ammunition.

He led you back through the beginnings of Snowdin forest  - the puzzles that were always ready for you _mysteriously_ not reset for once - and on to the deepest point you had even been able to explore the once or twice you felt up to completing so many puzzles to find it.

“... Please tell me you have a key,” you said as he stepped up to the door. You had held your tongue the whole way, unwilling to go back and deal with the tornadoes and the horrorshow their aftermath would be, regardless of what that meant for dinner.

Sans looked at the door, then upwards along the towering Ruins wall, stretching on well past what eyesight could gleam. You had previously noticed some rather deep gouges at odd levels on the door - but now with Sans next to it, you had a growing suspicious as to the source.

Finally, he glanced back at you.

***do you trust me?**

“Not really,” you said plainly. Still, a slight upwards quirk to your lips accompanied your words.

He chuckled.

***probably smart.**

You felt his magic put pressure on your soul before you were pushed back 10, 20 feet - but before you could protest, the pressure disappeared, and he simply held a hand up behind him to gesture for you to wait - and clearly, not for long.

The next moment that ever-more familiar tickle of his magic suddenly blazed forth as he opened his mouth, his legs spreading as he crouched forward, looking infinitely more feral as his tail whipped backward and what could only be _pure magical energy_ coalesced in his jaws within the bare span of a split second, blinding and nearly sending you to your knees under its sheer force-

The following moment you clapped your hands over your ears as a splitting _boom_ shook the forest and the cave itself as the energy discharged.

By the time your vision cleared, there was a gaping hole where the door had once been.

Sans cleared his throat slightly, as if he had simply just inhaled a little wrong.

You stared at him open mouthed.

When his gaze went back to you, he gestured towards the hole.

***a new and improved door, ready for use.**

A few moments passed before you finally shook your head, goosebumps across your skin even in his warm jacket. You moved forward slowly, some basic instinct in you trying to slam the breaks in incomprehension for what you had just witnessed.

A little smoke trailed out of his jaws as you passed him.

“I’d say remind me to not piss you off, but I think I may have crossed that line more than once.”

He snorted as he moved to easily step in front of you, ducking slightly as the trailing tunnel ceiling shortened.

***well, my machine scattered your sister across space and time, so… fair, really.**

“... Yeah, _fair_ ,” you said sardonically.

***fair when you consider i’ve got a magical super saiyan beam i can use.**

“Y’know, a lot of stuff suddenly seems a lot more fair when you put it that way.”

Admittedly, things seemed even _further_ amenable when you figured out that your apparently particularly magically overpowered skeletal… acquaintance? Quantum mentor? Captor-adjacent? … Companion…?

… either way, when you found out that despite his inclined laziness and apparently endless tolerance for salt, he could somehow cook the best quiche you’d had possibly _ever_ \- not to mention while continually ducking comically low even in the high ceilings of the larger monster house you’d entered, using only what old or foraged food items you could find in the since-sealed Ruins. You unabashedly _moaned_ at the first bite, having been fairly effortlessly warded off of sneaking an early taste by Sans. Outside of shooting him a look that was almost embarrassingly reverent for the shortest of seconds before fully devoting your attention to this absolute blessing in front of you, you couldn’t even spare Sans an ounce of attention to catch his reaction to _your_ reaction.

… Eating something other than ramen or popato chisps for the first time in a month and a half made this so, so worth the tornado terrors waiting for you back at the cabin.

\------------------------------------------------------

> **September 22, 201X**

Day three of your hunt was going about as well as the other two.

Still, you had it on good faith that _this_ was the payoff junkpile to sort through.

… Mostly because you had finally worked through most of the other ones, but _still_.

The Dump had become a bit more reasonably accessible to you the same day Sans had shown it to you, once you found out there _was_ in fact another way down here, if you were willing to get dunked in deep water for a comparably short span of distance. It was, in fact, the way you had to take _back_ , and you gave him ten minutes of grief for that, even though he wasn’t the slightest measure apologetic.

Considering the alternative route was the heart-attack-inducing drop for eternity, _hell yes you were okay with getting soaked_.

So even though it was quite the walk, you had been here ten times in the nearly three weeks that had passed since the first time. Seven of those had been with Sans - hunting for other food in part, a habit you were now _very_ insistent on after the quiche. You had sworn to him the next day that you would riot and find a way to trigger the now considerably smaller and reclaimed original trash tornado into another multiplying destruction session if you two didn’t at least _attempt_ to find the occasional alternative. You had also been hunting for _parts_ \- as it turns out, truly quality and reliable pieces of machinery had to be strung together from the husks of older garbage - _literal_ garbage - and you had to do it regularly, before anything new got too waterlogged to salvage.

It was the latter search that led you to understand just why Sans had so many tangled cords.

… You had actually caught him trying to untangle one such clump when turning to ask him about a piece you’d uncovered. He’d been too focused on his task and hadn’t noticed your movement. His clawed hands were nearly double yours in size, but he had nevertheless been trying with narrowed sockets to use his claws deftly enough to slide what appeared to be wholly busted earbuds from some finer cabling. He had sworn under his breath as one claw slipped and ended up slicing through the earbuds. The next moment he rolled his eyelights nothing short of _grumpily_ and with a flick of the wrist tossed what remained of the tangle into his usual bag.

He had turned to look at you then, only to see you observing an impressively long piece of copper tubing with an odd intensity.

Now, though, you were after something different. It wasn’t even something for you, but…

Dammit, fair was fair.

You grunted softly as you managed to flip a large hunk of flotsam out of the way to dig a little deeper. As it turned out, he wasn’t _entirely_ full of shit on the water heater front… Just two days ago, you had caught him rounding the corner in the deep snow from the side of the house where the water heater was tucked in a closet. The edge of a few tools were just barely visible poking out the side of his jacket pocket, but he had effectively ignored and dodged your questions as he walked back into the cabin.

The water was much warmer that day, far better than the point it had been cooling to.

And that was not the first time you had seen hints of it. It seemed like the water heater really was a finicky and slightly busted piece of work - which, when you admitted it, only made sense. Sans clearly didn’t use it, so it had laid in disuse for _at least_ five years, and even then given the usual standards of Underground’s tech and items - well-cared-for, but _very_ well used, given their necessary origin in the fucking _Dump_.

And now, there had to be a certain irony in the fact that apparently even fewer items were finding their way down here. Ever since monsters re-emerged on the Surface, bringing with them their inclination and incredibly practiced hand for reusing and fully recycling, your town had become something of a shining example of what reuse could really be thanks to the monsters. Your town’s dump had been actually _shrinking_ because of it… which appeared to be something of a direct correlation to the fact that fewer and fewer items were finding their way down to Waterfall’s Dump.

… So now here you were, having disappeared for the third day in a row, searching for something Sans had mentioned in passing that day he took you to make dinner in the Ruins. You were pushing your luck on timing, though - at this point, you knew Sans would end up looking for you if you were gone for more than three hours, whether out of suspicion or worry… or habit. Or maybe all three.

It took you over half an hour to get back, so you were going to have to throw in the towel in just a couple minutes if  you didn’t-

Suddenly, your eyes widened and you grinned.

 _Jackpot_.

35 minutes later, you bust in through the front door of the cabin, loot under your arms, nearly slamming the door in Sans’ face.

“Oh, sh-! I didn’t know you were there-!” You scrambled quickly in your words, unable to lift your hands to gesture as you normally would have.

Sans waved you off with a shake of his head.

 ***’s’fine, good timing otherwise, i guess, i wanted to- uh. what’s that?** An unreadable look came over his face. **… did you go to the dump without me?**

His eyesockets then widened as he realized the bags under your arms were far bigger and clearly _vastly_ heavier than they would have been normally on a trip with him.

“Yep, a couple of times,” you said cheerfully, ignoring the incoming argument you could sense at his registering your additional still-soaked appearance, and instead shifting to relieve yourself of one side’s bag. It hit the ground with a dull _thud_. “And it paid off, turns out,” you continued, shifting and hooking a hand around one of your prizes. You pulled it out with a grin, a sparkle of delight and pride in your eye.

You held out a restaurant-sized refill jug of ketchup to him.

“ _Ta-da~_ ” you murmured sing-song under your breath, waiting for his reaction, and...

You seem to have broken him.

Your grin grew a little wider.

“Come on Sans, don’t you want it? Promise it’s still good - in fact, I think it’s pretty fresh by our standards - and it’s even still _sealed_ ,” you said, shaking the jug lightly with an eyebrow waggle at his expression.

His jaw had fallen open, and he was frozen in spot, _still_.

“I mean, I figured since you said it’s been nearly a year since you found any - but hey, if you don’t want it, I’m sure I can find a use for it…”

It was out of your hands and held like a mug in his before you could blink.

You laughed at that. Your gaze caught on his own finally, and the bright intensity of his eyelights warmed you a little.

***... why…?**

You shrugged, tucking your hands into your jacket pockets. “It’s nicer when we’re on a level playing field, don’t you think?”

You moved to stack the rest of your loot under his desk for easy reach before he could answer, humming a little to yourself as you nodded at your handiwork.

“Alright, I’ll be back in a few, gonna shower off that sweet, horrifying dump smell. No need to wait to try it, if you don’t want to,” you said to Sans as you passed him, still rooted in his spot by the door.

You heard his voice only once you had closed the door behind you, muffled through the thick wood.

 ***... ketchup. she… she managed to find** **_ketchup_ ** **.**

The fact that you could hear the cap hit the door told you just how fast that thing had flown off of the jug.

\------------------------------------------------------

> **October 12, 201X**

***listen, i’ve heard of the dewey decimal system, but this is** **_point-blank_ ** **some next level shit.**

“Dewey Decimal was full of shit. I, however, am not.”

***okay well i’d argue that point, but in this case-**

Sans whistled low. The sound was nothing short of inexplicable coming from a skeleton monster, and firmly eerie for it, but the intended effect was clear in the face of your exploits.

His entire workbench and hoarded library of scientific knowledge was completely sorted and cleaned.

 ***... i’ll be honest, i didn’t even realize i** **_had_ ** **this many notebooks.**

You raised a brow at him and crossed your arms with a grin.

“Really? With how many of them you’ve chucked at me over the past couple months?”

***i get distracted by how funny it is to see you try and catch them.**

“Don’t get jealous of my mad ninja skills, Bone-Bowser.”

 ***i take offense to that - bowser** **_wishes_ ** **he had this jawline.**

You snorted. “Riiiight.”

Sans tossed you a wink, and you glanced quickly back to the workbench. That was the third time in the past week he had done that…

You shook your head.

“Anyways, what with how long it takes me to find the references and diagrams while I’m helping you build whatever reality-tearing excitement we’re working on, I figured it was about time it all got a new, proper home… with some things on the wall.” You nodded to yourself, looking at the array of larger notes and diagrams you had chosen to hang up with Sans’ agreement. “That’s some good hanging, if I do say so myself.”

Sans’ hands clacked together once, twice - he was slow clapping, you realized, and you shot him a look. He grinned.

***nah, really - i’ll easily admit, i’m no paragon of order-**

You grinned.

***yeah, yeah, smirk it up, sweetheart. like i said, i’ll admit it gets a little… dicey, sometimes, if i stress myself out too much - the, uh…**

His gaze shifted from yours, his tail whipping slightly as one hand went to the exposed vertebrae of his neck.

***... magic goes a bit haywire if i don’t keep a good hold on it.**

“... What happens?” You asked slowly, trying to keep your voice from spiking, keeping your tone even despite the unexpected shift in conversation.

You were unsurprised though when he waved you off.

 ***eh. doesn’t matter, i’ve got a hold on it. just don’t run after me if i start going all godzilla on the town.** He chuckled, but you decided to change the topic.

“So… you were gonna have me trapped in a cave for nearly three months, if things had gone according to plan, huh?”

His gaze went to you immediately, his brow ridges drawing downwards in confusion.

You gestured to the work area, to the pieces part carefully laid and the now-neatly organized volumes of notes. “It was gonna be me in a cave till you were done with the experiments, right? So, considering we’re this long in, and still not even close, I really would’ve been in the dark.”

***i wouldn’a left you in one that long.**

You raised an eyebrow at his grumbling,  a grin rising on your face again despite yourself.

“ _That_ long?”

***... tops a few days.**

“Oh, okay, only sensory deprivation for a few days-”

 ***maybe less! i don’t know, i had to do or say** **_some_ ** **thing to stop you from fighting so much, you were ready to bash my skull in with a hefty twig-**

“It’s a _good stick_ , Sans-” you laughed suddenly. “And besides, why the hell would you think that promising freaking _isolation_ would calm me down-?”

***figured if you knew i wasn’t gonna take your sister from you, not really, it’d at least buy a little time while you tried to hatch a longer-term plot, or whatever was racing through your brain-**

“That’s messed up.”

***and flawed, clearly.**

You cocked your head at him. His skull turned towards the machine briefly.

***... clearly, i wasn’t seeing what i needed to be more concerned about.**

… You both were quiet.

The machine still laid dark and dormant in the corner, no amount of work so far bringing it at least back up to the state it had started in. You knew that was the delay, if anything - whatever your sister had done, or however the machine had glitched, had effectively set you far back, and Sans was… being extremely careful to triple check any and everything he did to the machine.

Your elbow nudge his arm, drawing his attention back to you at last.

“... C’mon. Let’s look at that failed switch you were grumbling about yesterday.”

\------------------------------------------------------

> **October 30, 201X**

“I’ve always thought this was an odd way to lay out the history. It’s… really poignant, but not easily fully sequential, y’know? And there’s a lot of time interrupting the flow through them, even if you’re walking fast.”

Sans hummed, his feet kicking up more water than necessary, sending it slipping around your bare knees, nearly against the folded material of your pants. Your boots were secure in one arm - after this long, you were comfortable enough here to walk barefoot in at least some portions of Waterfall. The rooms nearest the plaques were among those, easily - mazelike as they were, they were some of your favorite areas. Besides, risking barefoot was infinitely better compared to the alternative of wet and squishy boots that took an obscene amount of time to dry.

***it’s… kinda like a memorial, i guess. I mean, we’ve got proper history books on the story, and it’s one of those ones you just… grow up learning, so i think the ‘flow’ isn’t something that’s so interrupted in the end. it’s really a loose history, anyways - this version, at least. like the simplified version you share at a fireplace to instill some kinda… reverence for history, or something along those lines.**

“Did it work?”

Sans huffed a laugh.

***pretty hard to forget where we came from when trapped under an enormous mountain.**

“... Touche.”

The walk was much needed. You and Sans had been working for nearly two days straight and had the shadows under your eyes to show for it, chasing what you thought was a promising theoretical lead in application - only to have finally reached a dead end earlier in the afternoon. After you both woke up from the following somewhat more frustrated nap-comas you had retreated into, you had all but dragged him out the door.

***you seem to like talking about stories and history.**

It was a reasonable observation after all the time you spent together, but you still found yourself looking away, a bit of heat rising unbidden in your cheeks as you shrugged.

“I’ve always been interested in stories, I guess. Plus there’s a lot of deeper stories about the Underground that… kind of went unexplored, I realize now, thanks to whatever vague ‘memory slip’ effects this new barrier has…” You bit your lip thoughtfully. “So it’s nice to actually get to know more. I think a lot of humans feel some kind of guilt - well, the decent ones, anyways - for what our ancestors did. I mean, it’s one of those things where-”

At that moment, your footing slipped.

With a squeak you tumbled backwards, eyes clenching shut in preparation for the splash and soaking-

… that never came.

Slowly, you opened one eye. Hovering just over you, his arm curled around your waist, was Sans - his skull was incredibly close to your face, his eyesockets only a fraction wider than usual. Water seemed to have dripped on his face at some point, a single bead of blue-tinted wetness rolling down his skull. Your hips pressed against his, nearly flush in his sudden grip.

***... you okay?**

You nodded, your voice not deciding to work at the moment.

It was like you were being held in a deep dip, and it seemed absolutely effortless on Sans’ part. You were having trouble looking away from him, the distant rush of serene water falls and the glow of drifting magical firefly-esque lights weaving some sort of trance-like state over you as you registered just how large his hand was, sturdy as it was at your hip…

***... hey, do you-**

Your free hand dipped into the water and quickly scooped upward, the speed boost of desperation providing mild force to your splash. Your eyes widened as his eyesockets did. As the moment stretched, an incredulous, sheepish smile spread on your face, feigning innocence.

***... oh, you’re gonna regret that.**

The next moment you were pushing out of Sans’ hold and fleeing from a desperate miscalculation in your nonexistent plan - his tail, whipping down into the water to form enormous splash waves. You shouted as you dodged, nearly tripping all over again as you simultaneously sought cover and a way to splash him right in the wickedly-grinning face, even as you were completely drenched by a wall of glowing water, blaming the color on your cheeks on the rush of adrenaline fueling your flight from your companion.

**Notes for the Chapter:**

> hm. i wonder what he was going to say...? 
> 
> (ps, even though i'm posting this quickly and it's 'short', so many thanks to VividlyLost and TyrantTortoise for leaving those sweet comments on that first chapter-! i'm still adding to this as the day passes because that's just _who i am apparently_ , so that absolutely made my day! you're both gorgeous souls and i appreciate you so much ;v;)


	3. Steady, Steadier, Yet Steadier

**Summary for the Chapter:**

> The Scientific Process:  
> Observe.  
> Ask a question.  
> Form a hypothesis, or testable explanation.  
> Make a prediction based on the hypothesis.  
> Test.  
>  _Test._  
>  _**Test.**_  
>  Refine. Iterate. Repeat.

> **November 11, 201X**

“I… I think I would’ve had zero shits with naming, too, if I had to walk through here covered in as much fur as Asgore is…”

***he’s always been the worst with names. or the best, i guess, dependin’ on your humor.**

“So, the best, basically.”

***never run out of joke ammo with it, that’s for sure...**

“ _ Hotland _ though, I just…” 

You shook your head, already down to a tanktop you had procured and a cutoff pair of shorts from a less-salvageable but at least mildly fitting pair of pants. 

“Yeah, y’know what, I don’t even have the energy to  _ care _ in here. Cheers to you, Asgore, you to-the-point kingly bastard.”

With a weak wave of your fist you mock-saluted the cave ceiling above you, as if generally aiming towards his existence on the surface.

***we’ve only been in Hotland for 5 minutes,** Sans said, his voice low and lacking any attempt at hiding his amusement.

You groaned.

“Listen, I grew up in the north, and  _ not _ in a place with vastly different contained climates. Anything above 80 degrees is verging unbearable as is - but 100-whatever-the-shit degrees above a  _ literal lava pit _ is gonna leave you with a, with a-” Your hand vaguely gestured as you faltered. “-a human with a…  _ whatever _ .”

***descriptive.**

You lifted a lazy thumbs up without looking at him, your head no longer willing to lift from its hanging position as you trudge forward, sweat beading across your skin, sticky and gross and beyond unwelcome. He laughed at that - but despite his egging on the subject, he seemed less than comfortable as well, the sound of his chuckling fading faster than normal with a forceful exhale.

***hey, on the plus side- we’re already here** , he said, his tail lifting and brushing you in a mimic of a tap on the shoulder.

Your head lifted, relief still distant in the mugginess of your inability to really function at the moment. Above you loomed a surprisingly brightly-painted building simply labeled “Lab”, it’s corners meeting the cliffface drop into lava on either side.

Wordlessly you trudge forward once again, now shambling more like a zombie on a mission than one lost in a field.

Sans’ form quickly moved ahead of you, and he pried the door open with relative ease and let you in first.

You nearly sobbed from the gust of cool air, not caring much about its particular staleness with how familiar the state of it was in the caves thoughout the Underground.

***yeah, the ac here is one of the few things i bother to try to keep running,** Sans said as he let the sliding door snap shut.

Opting to drop to your knees and fall unceremoniously onto your stomach, you groaned in reply.

A single emergency light on a little further in the room was the only thing lighting the area, and from your brief semi-coma on the floor, you could make out a seemingly hastily-cleared out informal lab, surrounded by nonworking escalators, and what appeared to be some kind of door over which the light was positioned.

“This floor is my home now, I hope you know.”

Sans snorted as he approached, and from the corner of your eye you could see the grin spreading on his face as he shook out - his hoodie flared and he snagged at it, flapping it as if to release heat trapped inside.

***it’s cooler in the true lab.**

“... You speak my language, boneboy.”

You grinned as you managed to flop over and eye him from your new position on your back. You rose a single brow at him, as if considering his words heavily. An odd look passed over his skull as his gaze was pulled to yours, but considering his minimal pause in still lightly flapping out his jacket, you decided not to linger on it.

With an exaggerated sigh, you rolled around and pushed to your feet.

“Very well, the arduous and draining journey continues, then.”

Your effort to grandly gesture for him to proceed forward fell a little flat with how you let your arms flop back. He rolled his eyelights at you, but in a few unrestrained strides he moved to an escalator with a short wave at you to stay put. It gave you a moment to wander in your thoughts - when he wasn’t holding back to walk in a way that suited your stride, he could cover an absurd amount of ground. The bones of his lower legs were thicker than you’d ever expect of a skeleton of any variety, even a giant beast of one. It was fascinating to watch the bone shift smoothly with his movements, joints plating together and seemingly fastened or otherwise bound deeper by what could only be magic. He effectively  _ leapt _ up the escalator, looking completely effortless and uninterested in what should seem like a feat of strength. His movements did something odd to you when you watched him like this, moving at his own pace and without the usual constricting space even in his oversized cabin…

He was back in front of you as you blinked, his taloned feet hitting the ground as you muffled a yelp at his appearance.

***i’d say that i hate to** **_drop in_ ** **, but…**

Apparently, his preferred level of returning back down to the main level was to leap the low railing of the second floor.

“You’d be a damn liar,” you said, glaring up at him without an ounce of actual malice. 

He shrugged and turned towards the door under the emergency light as you noticed the low hum of energy from behind it. 

***can’t say i’ve got an argument to that, sweetheart.**

You rolled your eyes as you followed after him, the heat still lingering on your skin.

With an elevator now running on what was apparently a specific line of backup power, you and Sans were able to start your way down to the ‘true lab’. The only light in the dark box was a dim red one, and you couldn’t quite tear your eyes away from the way it shifted over Sans bones, gentle crimson catching shadows in the nicks and grooves of his chest, sloping along the trim of his ragged jacket, deepening the dark circles under his eyesockets, casting starker shadows along his sharp canines and the crests of his horns. You pressed closer to your corner, trying to give him as much space as possible as a resigned and annoyed expression settled over his skull for how much he had to duck and squash to fit.

The elevator stuttered and shook then as the light flickered, sending you slightly off balance, and causing Sans to need to brace himself as the elevator briefly threatened to stop entirely.

His forearms braced on adjoining walls of the box, framing you as he was forced closer still to you. Your eyes widened as your own arms went out to steady yourself. He inhaled sharply as the elevator halted, the sound nearly lost in the grinding of some different machinery.

***... it does this sometimes, gotta… give it a minute,** he said, his voice lower both in tone and volume than usual. This time more than any other, you really  _ felt _ his voice more than heard it - as if it was something more than sound, transmitting directly to your consciousness instead of passing through the air around you.

“Seems on par with our luck,” you replied, your chest tight.

Your gazes were on one another, neither of you seeming to dare to even breathe.

The red light of the elevator cast a dim glow over your own skin, but it seemed so much  _ more _ catching over his bones, somehow. Anywhere over the slope of them that you weren’t focusing on, you swore you could catch a shimmer of something glimmering over their surface - but the moment you tried to focus on it, it was no longer seen…

The elevator rocked again suddenly, and one of Sans’ arms slipped further, brushing against your arm as he was sent closer yet to you. You reacted quickly, instinct winning out, trying to catch him-

Downwards movement resumed as your hand found steady purchase against his chest, the flat of your palm against the material of his jacket, your thumb brushing over its edge to slip against his sternum as he regained his balance.

Something utterly electric and  _ warm _ hummed against your thumb for a moment.

The next, you had pulled back your hand without thinking, finding yourself embarrassed with no understanding as to why. Your hand hovered an inch above his ribs, and his jacket fell back into place.

“Sorry, I didn’t - I mean-”

***it’s fine.**

The rough and strained quality to Sans’ voice made your heart pulse painfully at once, and despite your instincts screaming at you to look  _ anywhere _ else, your gaze was drawn back up to him.

His eyesockets were closed, to your surprise. With the light behind him, you couldn’t make out much detail of his expression, just the downward slope of his brow ridges, furrowed almost, in the red outlining glow framing his form leaning over you…

The elevator stopped suddenly again and the doors shifted open without hint of hesitation. 

The hesitation was only in Sans, for the barest moment - and in your own chest.

… The next moment he was ducking quickly out of the box, stretching back to his full height in the dark of the room on the other side of the doors.

You followed after a moment, willing yourself to breathe normally. Distraction clouded you in the moment and before you could register your surroundings properly, you heard the elevator door shut with a soft snap, and you were plunged into darkness.

“Wh- Sans, why are the lights out…?”

Your voice was steadier than you would have given it credit to be.

***the lights are-?** His voice sounded distracted, but he cut himself off.  ***... oh, right. shit.**

“... Sans. Did you…  _ not  _ notice the  _ complete lack of definition in our surroundings? _ ”

***... no?**

Your hand smacked against your face, echoing muted in whatever space you were in. Being in the complete dark like this was more unnerving than you would have expected, but focusing on him was helping.

Something occurred to you with the trailing tick of his voice.

“... Can you see in the dark?”

Silence.

***... maybe.**

The sound of your hand meeting your face filled the room again, followed by mumbled half-hearted curses from you.

Finally, “Well I  _ can’t _ , so I’m not sure if I can be of any help on this field trip,” you muttered.

***i mean, you’re still pretty** **_handy_ ** **if i do say so-**

“I swear if your pun is literally only off of the fact that I  _ have hands _ I will stumble blindly until I can grab your tail and-”

***there’s an emergency generator down here,** Sans interjected with a chuckle, cutting off your threats in a practiced manner.  ***sorry, i - well, obviously it’s only been me down here, so i forgot to get it going.**

You lowered the hand that you had ineffectively risen in the general direction of his voice. “... Yeah, alright, certainly beats hanging in the creepy pitch-dark basement twiddling my thumbs the  _ entire _ time. I guess I’ll wait for you to turn it on, just make it quick-”

***nah.**

Before  you could react to his flippant answer, you felt a brush of bone against your hand and was forced to bite down a scream as you jumped. Sans’ hand wrapped around yours for a brief moment as your heart rate spiked, blood rushing to your face as you froze. A hint of that buzzing, humming energy passed through you before it was quieted, and the next thing you knew he was placing your hand on his forearm, tucked around his arm as if he were-

***i’ll be your escort,** **_m’lady_ ** **.**

There was a mischievous grin in his voice, and it had come far closer than it had been.

“I’m gonna trip all over you,” you managed to say, finding your voice.

You felt yourself pulled a little closer to him as it seemed he pocketed his hand in his jacket.

***i’ll** **_arm_ ** **myself for the probability, sweetheart.**

At that he started walking, prompting you to follow his movement as his arm tugged forward. You quickly reached up with your other hand, placing it on his forearm as well and willing yourself not to grip too tightly.

“Don’t try and  _ trip me up _ with your wordplay, you jerk,” you groused, a smile playing at your lips even as you found it increasingly unlikely you were going to get your heartrate down.

***don't get your feet under my wordplay,** he quipped. You could hear the smirk in his voice. Your eyes were straining wide, as if there were a hope of adjusting to the pitch-darkness enough to gain some form of sight.

“So you'll  _ sentence _ me to a fate with the floor?” Your hands tightened on his forearm a fraction as he leaned towards you – steering you to one side. Understanding the hint, you tried to adjust to turn the unseen corner.

***only for a** **_period_ ** **,** he replied offhand. You huffed at his not missing a beat, and then nearly tripped once again as he veered only slightly to the other side. Little things were catching at your senses now – it really  _ was _ chillier down here, almost making you regret your wardrobe if not for so recent a memory of the horrifying heat outside the lab.

“ _ Comma- _ n, through a girl a bone,” you said, the wordplay coming ever easier over time.

The footsteps between you were echoing slightly now, the soft chuff of your boot on concrete or... maybe some kind of hewn tile, pairing familiarly with the surprisingly quietly clacking of his bone talons.

***well, it's a point in your favor that i can** **_colon_ ** **you when I need an extra pair of hands** . His voice sounded strained for the slightest seconds. The toe of your boot caught on the edge of uneven flooring then, and you stumbled and nearly tugged his arm out of it's easy resting position.

Without a chance for you to even fall enough to lose your grip, his tail was around your other side, just enough pressure in its presence to right you and steady you.

It was gone before you could react, and he led you around another corner.

***maybe not when i need an extra pair of steady feet, though.**

His voice was strained again, but in a different way, curved with the lilt of his smile-

“Sorry I don't have raving nightlights for eyeballs,” you retorted, your breath shorter.

He choked, somehow, despite his utter lack of a throat – truthfully, they weren’t quite  _ lights - _ after all, for some explicable reason, despite their appearance, you couldn’t see them now. His arm shook and invariably had you pulling closer to him, and the sound of muffled laughter rumbled through his bones, even reaching your finger tips, bringing – for a moment – that buzzing energy back into awareness as you focused on him harder, a grin unknowingly spreading on your own face.

***n-nightlights,** he choked out, taking the turn for a corner a little sharper than he had been. You had less issue following him though, nearly pressed to his side as you were now.

“You heard me, you giant Halloween decoration.”

***as if you ever had any crappy plastic decorations that came close to** ** _this,_** he replied. The tone of his voice was more controlled again, and you had the distinct impression that he had just gestured to himself with his free arm, a shit-eating grin returning to his skull.

“Yeah, I'll give you that – you're more like a glorified cosplay,” you said, causing him to snort. “Those are some well-sculpted bones.”

He choked at the same time your mouth snapped shut. His arm suddenly acted as a more literal anchor as he stopped, forcing you to quickly catch yourself. Your thoughts and heart-rate spiked, and you couldn't even find the means to curse under your breath at your weird,  _ weird _ slip-up, and you tried to find a way to blow it off or reword it, before he was too off-put, or maybe worse yet-

The sound of panel keys being quickly tapped broke through your thoughts, and a moment later you heard the snap of a large switch.

You blinked furiously as lights burst into light around you, blinding you far more literally than you had been in the dark as you tried to adjust.

***gotta say, that's one of the odder compliments i've gotten, sweetheart.**

You started to make out his face, but a weird hazy glow was over his skull. You blinked rapidly again.

***that expression is** **_humerus_ ** **enough to make it worth it, though** , he added, and that sound of a grin in his voice finally aligned with your vision clearing. The tinted haze over part of his skull was the last thing to clear up, oddly enough, but you shook your head with a grimace, recognizing the heat on your cheeks.

“You know what I meant,” you grumbled, looking away quickly. The room was large and more than slightly dilapidated, with the exception of the slightly better tended machinery you stood next to, particularly what you could only assume was the generator itself.

***sure did, sweetheart,** he shot back, his grin growing.

You lifted a hand to punch him lightly in the forearm, ignoring the smarting consequences of the playful strike. 

“Clearly not!” Your voice broke into a laugh as the lights overhead mercifully dimmed – almost too-dark again, like it was lit for the evening, but you could still see plenty well as you shook your hand out, the knuckles predictably aching.

***nah, my powers of observation are too good for that,** he replied, and you received a wink for your trouble.

“Give a guy a science job and he thinks he's infallible,” you said, rolling your eyes.

He shrugged and you were on the strange receiving end of what was clearly his equivalent of the waggling of his brow ridges over the crest of his dragon-shaped skull.

Despite your distraction at the odd and hilarious sight, his shrugging made you realize that you were still holding onto his arm. You laughed at his expression, flushing slightly and using the movement to quickly step back, your arms flying a little too quickly away.

“A-alright, come on you big scary nerd, let's go get some magical science doodads,” you said, quickly turning away and moving towards the only door in the room.

***always a fun experience to hear priceless reality-testing scientific equipment referred to as a 'doodad',** he drawled, passing you easily to duck through the too-short doorway and turning a corner.

“Don't hear an argument, nerd.”

***technicalities, sweetheart.**

You trailed just behind him, the hallways a little too narrow for you both to walk side-by-side. It gave you a moment to regain yourself and let your focus wander as you did so, a small smile forming on your face at the sight of his tail dragging just a breath above the ground to prevent any noise, but slowly twisting back and forth as you had noticed it would when he was in a decent mood. The line of his back was the only hint you had that he wasn't entirely at ease – despite his usual slouch, the line of his vertebrae visible between the bottom of his too-small jacket and his shorts showed a stiffness that... threw up a few flags for you, considering he usually either held himself fully aloof and lazy, or showed a much more full tension when his stress and frustration had grown.

… A lot of time had passed since you had fallen down here. Your right hand went to your left wrist, brushing over the woven material of your bracelet.

You decided to put that thought aside for now.

“So this is the only lab-type facility I've seen or heard of down here, outside the one in your cabin,” you said, tone light. “Did you... work here?”

***if you wanna get technical about it, the entire Core is basically an elaborate energy lab.**

You rolled your eyes at his guff. “Who was the one just talking about 'technicalities' in an argument...?”

He huffed a short chuckle, stopping as his hand met a panel next to some blank screens down one stretch of hall. The wall perfect matched the rest, but he pressed his hand down firmly as magic sparked in his eye and flared around his hand. A few grinding and clicking noises were heard muffled behind the wall, and then a portion of it swung open, revealing a staircase that curved downwards.

He stepped in first, glancing behind him and shifting his tail to the side to make room for you to follow him more closely.

***... yeah, i worked here,** he said, turning his attention back forward as you stepped closer to him, one hand going to the inner curve of the wall as you both started down the staircase.  ***worked for a long time, actually, but i left eventually after a... well. eh. mostly wanted to be around more, the lab always had me around for late nights and... yeah.**

The shrugging of his shoulders shifted the frayed fluff of his hood. Your brow had furrowed, trying to parse out pieces you were finally able to put together, though your mind drifted for a moment. In the several months you'd been down here... Sans always wore that hoodie. It was easy for him to wave you off when you had gotten fed up and tried to get him to let you wash it, as he informed you that skeleton monsters – and monsters in general – didn't do 'gross human things' that would cause them to get dirty, and he was unswayed by the logic that his clothes weren't excepted from the effects of the environment and, worst of all, the Dump. You hadn't been able to find anything whole or large enough in your trips there to fit him, though – even you still only had your original leather jacket as an overcoat, and nothing else had been suitable enough for him or his apparent lack of taste.

***science has always been in my** **_bones_ ** **, though, i can admit that,** he continued then, playing off his almost-admission with the curve of his usual grin visible even at this angle.

“... Did your brother work here?”

Sans exhaled a little too hard.

***yeah. headache-forming interests are apparently a family trait,** he said. He didn't look back at you, though, and you wondered what else the lilt of his voice was concealing.

“You... had to get away after whatever happened, huh.”

It wasn't pity in your voice.

***...**

You wished it was less laden with absolute empathy, truthfully. You wished you didn't understand.

“... I'm sorry.”

The staircase wound ever-downward, and the air cooled further, raising goosebumps on your skin.

***so am i.**

Your brow furrowed again at that.

“How do you mean..?”

A self-deprecating half-chuckle left him, his oddly echoing voice hitting you deep within your own chest again.

***... you're the only one who may actually know what it's like, at least a little,** he said simply.

The pieces slid together.

“Sans, you – you saw him, didn't you...? He-” You tried to swallow around the lump in your throat, willing your voice steady and soft. “Whatever he was working on... he got torn into the Void, too, like...?”

***like your sister.**

The goosebumps spread further as the air chilled more.

***... i'm the only one that remembers him, because of it.**

You stopped, all but freezing in your place on the staircase. He stopped too, not needing to spare a glance behind him.

“... How?”

***apparently, the Void likes to live up to the name we gave it,** he said, dry and hopeless humor barely tinting his flat voice.  ***it's not just your existence on a plane or in a timeline that's** **_voided_ ** **– or rather, it's not just voided** **_at that point_ ** **.** His skull tilted upward slightly, staring unfocused towards the ceiling, any trace of his usually put-on grin gone.  ***you're erased from the timeline...** **_completely._ ** **you're no longer anchored to a point in time – and unlike what some sci-fi'd have you believe, that's not the ticket to all-powerful influence on mortals, or whatever the shit they say.** His voice almost slipped to a growl, but the flatness came back just as quickly.  ***your bond to time is severed. your bond to space –** **_this_ ** **space- is severed. and you're swallowed whole by an infinite, immeasurable nothingness, that both exists and doesn't exist.**

His skull finally turned slightly towards you, though his eyelights stayed focused on an interminable distance.

***my brother and your sister... by all other accounts, they never existed.**

He accepts your silence without surprise, or distress, or – anything.

For the first time, you were seeing Sans with his guards dropped, and even the confidence that you... never really realized had been there, or assumed, had fallen away.

A small exhale, and his skull turned back forward.

***i'm... not sure what the exact reasons are, but something about witnessing the event makes it possible to remember them. but i was the only one there when it happened with my brother. and the two of us were the only ones for your sister.**

“... No one else could remember,” you whispered.

Your right hand was vicelike around your left wrist, over your bracelet.

***not even family,** Sans replied. That dry, hopeless half-humor rose for a split moment as he said it, and his eyesockets narrowed as his brow ridges drew down.

You couldn't bring yourself to ask the question that arose at those words.

“... I... don't blame you for leaving the lab after that.”

His skull turned towards you, but this time his eyelights were focused on your face, dull but complete surprise in their dim light.

“Whatever happened in between the event and your leaving...” your own eyes shifted to the side, unfocused as your own painful ache throbbed in your chest. Your fingers drifted over the material at your wrist. “I doubt it was instantaneous. But... under the stress of the work, and no- no one else remembering your own  _ brother _ -” you took a shuddering breath, forcing yourself to meet his gaze. “... I've been... angry. Angry, and frustrated, as much as I've been trying to reign it in. This... this is taking  _ so long _ ,” your voice cracked, “-but – but this is anything but the first time you've gone through this, and... you're trying so hard to... not slip up, I think.”

He remained silent, but his eyelights flickered. Something in your chest resonated and echoed with pain and empathy, nearly bringing you to your knees.

“... So... I understand leaving it behind, for however long. I just...”

You struggled to find the words, too many things tightening and cutting your words off in your chest as heat and wet threatened the corners of your eyes.

***... thank you.**

You took a breath, trying to see through your tears.

***... for understanding.**

You couldn't make out whatever it was that was dragging such deep shadows under his eyes, dimming the lights of his eyesockets – but the raw honesty in his voice reached you.

“... Thank you for not giving up,” you said, your voice almost too quiet to hear.

There was still too much unsaid, but...

Sans' hand lifted, passing a hair's breadth over your arm, only to hesitate over your cheek. A track of tears you hadn't even registered slipped down your cheeks.

Finally, his hand shifted, and with the lightest brush of one of his claws, he swept a loose lock of hair away from your face.

His gaze remained on yours for another beat, then he pocketed his hand once more and turned to face the downward trail of the stairs once again.

***... one way or another, we'll figure this out.**

He never said the words explicitly, but you felt the echo of a promise buried deep.

“... Yeah, we will.”

His body shifted at last, and he began to walk down the stairs again. You took a steadying breath, wiping quickly at your cheeks. After one more breath, you nodded to yourself, and followed after him.

\------------------------------------------------------

> **November 26, 201X**

The room was quiet, making it all the more jarring a noise when you kicked one of your surrounding boxcrates as you jumped to your feet, a victorious smile on your face – which grew wider as your eyes flashed to Sans, and in mild relief, you saw him still deeply asleep.

You still weren't sure how you had managed to hide it for these couple weeks, considering how erratic his naps were, and how much material you had to carefully hoard. Hell, maybe he  _ had _ seen it, and simply hadn't said anything.

… nah, he'd never pass up the chance to be nosey about something more out of place like this.

So it was with admittedly nervous energy and excitement that you quickly attempted to fold up the large creation in your arms, half giving up when you figured he wouldn't care much about presentation, anyways.

With soft steps you padded over to Sans' pillow-and-blanket pit, taking care to step over his tail trailing along it's edge. You hesitated, not willing to step onto his bedding proper – even these four months in, it was the one part of the cabin that you  _ hadn't _ ended up lounging on as you worked through some aspect of the machine's latest issues or needed developments.

You settled on toeing the edge of it and cleared your throat.

Sans didn't wake up, entirely unsurprisingly.

You steeled yourself, grin growing wider with your nerves.

“Hey, Sans,” you called, your tone still a bit soft.

Nothing.

“Saaaans,” you repeated, louder this time.

His expression was pretty dopey when he was asleep, wasn't it?

“Hey! Science dude! Wake up!”

… Damn, his tail was too fucking cute when it flopped like that. Not that you'd ever admit it.

“HEY, LAZYBONES!”

He groaned, curling up further with a grimace.

You grinned again, the heat still present on your cheeks.

“Yeah, yeah, just look over here, okay? I've got something for you,” you said, trying not to laugh at his attitude. You weren't exactly one to talk when it came to waking-up reactions.

He grunted, curling up a little tighter with a furrow to his brow – but relented, his body rolling just enough to better face you as he cracked an eyesocket open.

***c'mon, sweetheart, let a monster get some-**

His voice cut out as you unrolled the item in your hold, presenting it in front of you.

“Ta-da,” you half-sung, masking your nerves poorly.

His eyesockets widened.

You held a frankly  _ enormous _ hoodie in front of you, hand-stitched together from as much matching and warm material as you could find. It was patterned in deep blues and midnight blacks, with thick hood with an inner lining of dark, soft flannel. You had fashioned a fairly deep V down the front to make room for him to slide his skull through, but it had thick, simple lacing almost like a poet's shirt to allow him to easily close most of it up.

Most importantly, you had fashioned the warm garment to be long, and fully in his size.

He remained silent, so you shook it slightly at him and started rambling. “I noticed, I mean – obviously, but you know – I noticed that your old hoodie was... er, small, to say the least, and really worn, and... I know we never find anything in the dump that'd fit, so, well, I finally figured I ought to try and make something. I'm not the best seamstress or anything, so it kind took a while, plus I wanted to try and make the patterns look decent rather than just cobbled together fabrics, and I had to start over a few times to fix some dumb mistakes... and I mean, right around now is a holiday on the surface, er, for the country I'm from anyways, and while it has kinda shitty origins it's basically about being thankful for the things that you oughta be grateful for in your life, so since we can't really afford to swing wasting or making a bunch of food like'd be tradition, I thought it'd be nice to make you something that'd be nice, but- uh, I mean, if you don't like it, it's okay, no pressure-”

Sans sat up and carefully took the hoodie from you, effectively shutting you up.

Even sitting, he was a little over at eye level with you, and you had to tilt your head to try to analyze the expression on his skull.

***... you... made this?**

You nodded, not trusting your mouth after your vague monologue.

His gaze tore away from the hoodie to yours. His eyelights were bright and wide, the sleepy sluggishness of his previous expression wiped away. He opened his jaws once, twice – but snapped it shut, his gaze turning back to the hoodie for a few seconds.

***holy shit,** he breathed.

Your chest tightened hopefully.

“Uh, holy shit  _ good, _ or...?”

His gaze went back to you, and after a moment he set down the hoodie, nearly making your heart drop – but the next moment he shrugged off his current zippered hoodie and placed it carefully to one side before quickly lifting yours, gently tugging the lacing at the neck looser.

An undeniable blush rose over your face at his actions and... at the rare sight of his completely bare upper body. You quickly, lightly slapped your hands to your face as his skull disappeared in the torso of the garment briefly. Your hands rested on your cheeks in anticipation as his skull pushed through the opening, one of his large horns only briefly catching on the hood before he shook it off. His arms pushed easily through the sleeves – you had tied to gauge it right so they'd be loose enough for comfort, but tight enough to not get in the way when he was working on some more delicate aspect of the machine, and from the looks of it you were successful. It was thankfully long enough too – you silently blessed how much you'd been working with him on measurements and theoretical workings lately, it'd given you some practice in that department, passing well-fitted over his pelvis and ending at the right spot to not really interfere with his tail.

Sans rolled his shoulders as it settled over him, briefly tugging the hem down, stretching his arms experimentally and – almost  _ reverently _ . He tucked his hands into the large pocket you had sewn onto the front, but at the moment left the lacing of the V still loose.

“... Do you like it...?” You ventured as he removed his hands from the pocket again, finally noticing the reinforced thumb-holes you added to the long sleeves. He looked up at you, jaw opening again.

**_*holy shit, yes_ ** _ ,  _ he said emphatically, a grin of utter disbelief finally spreading over his expression.

You exhaled suddenly and forcefully, your hand shifting over your heart and your grin finally relaxing into something bright and relieved.

“Thank the stars,” you swore, finally dropping to sit at the edge of his blanket nest.

***how- seriously,** **_thumbholes??_ ** he emphasized, his thumbs slipping through the feature in question before he pushed his arms out straight in front of him, his grin spreading as his sleeves naturally stretched with the movement, not bunching up above the wrists like it probably would have otherwise.

“Aren't they the  _ best _ ?” you said, propping your chin in one hand as you shifted to lift a knee for your elbow to rest on.

***yes,** he replied, no hesitation.

You laughed, a light blush still persisting on your cheeks as your heart beat fast with your ever-lifting mood.

“So.. you like it, overall? I tried to make it fit well enough to be cozy, and not get in your way, and the hood's line with flannel to help weight it and keep it warm – I know your horns probably get in the way, but I can modify it in whatever way you want to make it work comfortably-”

He gave you a simple look and your mouth shut with a snap.

***sweetheart, this is... one of the nicest things anyone's ever done for me.**

Your blush darkened.

“I don't – I mean, I'm just... just happy you like it,” you said, waving a hand at him.

He shook his head, his gaze capturing your fleeing one. He smiled at you, the curve of his jaw uncertain, vulnerable, but utterly sincere.

***seriously... i love it.**

Your heart fluttered.

“Heh. Happy Thanksgiving, Sans.”

\------------------------------------------------------

> **January 3, 201X**

***remember the code?**

“Yes, yes, blue stop signs – c'mon, Sans.”

***immediately. any discomfort, or weird feelings at all – and just... keep describing it, like we planned, alright?**

“I promise,” you swore, meeting his focused and tense eyelights.

Your own pulse was going too fast, nerves lighting your guts with butterflies, but you had been planning this for so long now, and desperately needed the results to continue the research.

***... remember, it's just a test run. we can always try again in the future.**

Sans wasn't letting go of your gaze, and the less nervously-impatient part of you was actually extremely grateful for that.

You nodded.

He held your gaze for a moment longer as if looking for any doubt in your eyes, but finally exhaled when he found none. His gaze dropped to your chest, and you took a deep breath.

He was sitting in front of you, and you rested on a few blankets and a pillow perched on top of the largest boxcrate from your corner to prevent you from having to crane your neck to look up at him.

His hand hovered over your chest now, and you took another steadying breath, ready to start describing whatever you were feeling of note.

Today, for the first time, he was pulling out your soul.

It was a necessary step – human souls were laced with incredibly potent and concentrated power, and yours was the only one available for study. You both well knew that soul power was somehow the key to the machine working and connecting to the void, so once you had done all the work you could manage before needing to look into this side of things, you had little other option to move forward.

… And, as Sans had admitted, it made it infinitely easier that you two were... well. Certainly no longer antagonizing presences for one another, not in a very long time – and a hell of a lot more than acquaintances, or even... 'companions'.

… Friends?

… Something like that.

You tried to refocus on the moment as Sans' gaze slipped to your eyes one final time. You met his gaze resolutely, and nodded with the smallest of smiles to reassure him.

He nodded in turn.

You felt a sparking pressure at your chest, and inhaled.

Quickly, before Sans could back out, you began explaining. “Just – wow, okay, I feel... a pressure. Not bad, just – weird. Like I'm aware of something in my body that isn't exactly physical – oh,” you half-laughed, memory coming to your aid as you felt Sans slowly resume pulling. “It's like – when you used your magic on me, that first day,” you realized.

He grimaced slightly, still focused on your chest.

***good to know that memory's still wholly intact,** he mumbled.

You resisted the urge to shake your head, feeling a little breathless. “No, it's fine – technically, whatever  _ hold _ you had on my soul didn't hurt, not really, just the... y'know, slamming into a wall.”

***even better.**

You bit down a laugh. “Mistakes were made,” you said lightly.

He sighed, but only briefly – the next moment his eyelights sparked with recognition, and you gasped as your chest tightened, then all at once, burst with light.

In front of you, feeling exposed and utterly consuming over your attention, was a brilliantly golden yellow cartoonish heart.

“Oh,” you sighed, your eyes widening, and tears coming to your eyes for no reason you could find word for.

* **... wow,** Sans breathed, his hand hovering underneath your soul so, so very carefully.

“That's-” you quickly and gently wiped at your eyes, trying to remember why you were doing this. “Okay, it's – wow, it's really – I feel... exposed, and kind of – raw? Every feeling is – is electric, is  _ strong _ ,” you tried to explain. And it was true – awe and concern and excitement and anticipation and hope and desperation and desire and intrigue and so much more blazed through with a staggering intensity.

Sans nodded, his eyelights resting on your soul with incredible focus. The rest of the room faded around you, until all you could really focus on was your soul hovering above Sans' hand, and Sans himself.

***that's all normal,** he managed to say, his voice odd and almost a caress against your soul, in a much more visceral wave of what you had noticed before with his voice feeling like an echo against something deeper within you- but now, it wasn't deep within you, and it was infinitely stronger than an echo.

“Your voice,” you whispered your eyes widening as your gaze barely managed to tear away from your own soul. The raw emotions roared within you, no one able to claim dominance, but bring tears to your eyes in understanding and delight, sending your heartbeat racing in confusion, excitement, fear, interest- “-I hear it... in my soul? This whole time, I hadn't been able to place what it was, I mean-” Your face rushed with blood, your embarrassment so much stronger than it had any right to be- “I – you have a nice voice, I just – sometimes, and more often lately, I feel like I'd  _ feel _ it as much as hear it, somewhere inside of me-”

Sans' eyesockets widened as his gaze tore from your soul to meet yours. He looked almost monochrome with how beautifully pure a yellow your soul shone, as if color had never been true enough before you had seen it.

***you...** **_felt_ ** **my voice? in your soul?**

Confusion, intrigue, worry, embarrassment-

… Those weren't coming from you?

“And- I... I think I'm... feeling what – no wait, it's more like it’s... easier to guess what you're feeling, like this?” Your voice was still breathless, honesty easier for some reason now.

Sans watched you, and you almost felt as if his emotions were muting slightly as a look of concentration crossed his face - but they were back just as quickly, and you shook your head in answer to his unspoken question. His face glowed in the light of your soul, and very, very slowly, he began to draw his hand away, glancing from your soul to you, looking for any change in you.

Your brow furrowed as you found it nearly impossible to fight a frown, visceral... disappointment?... rolling through you. Slowly but surely, it became harder to sense his own feelings.

“It's – I can't... read you as well now,” you said slowly, the frown winning out without your realizing.

You were annoyed now, then relieved, then confused, then staggered with a rush of too many emotions to name as you couldn't quite read what the shift in his expression meant, even your normal growing ability to read his expressions over time failing you with how distracting the experience of all of this was.

***okay, that's enough for now,** he said softly. Your eyes were narrowed, screwed in concentration as you tried to sort through everything – finally you nodded.

With careful reverence and a gentle hand, he guided your soul back to your chest.

Your energy fled and you collapsed as the room popped back into full color and focus at it's return.

You weren't even given the chance to tense for the impact of the floor before Sans caught you, his arm supporting your upper body as his eyelights scanned your form with his brows knit.

***are you-?**

You took a breath and blinked your eyes, but gave him a weak thumbs up.

He let out a breath you hadn't even registered him holding.

“I feel like I need about twenty naps 'n thirty snack breaks... and coffee. So much coffee,” you mumbled, unable to lift yourself back up right.

***a girl after my own soul,** Sans laughed quietly in relief, the sound rumbling soothingly through him to you – but his eyelights quickly shifted away. Your brow furrowed in exhausted confusion, but from the direction, you figured he was looking towards your nest of blankets serving as both your long-time bed and personal area.

“Just – give me a minute, I'll get up and rest, 'n we can talk out all that-”

You squeaked as suddenly you found your legs swept from off the boxcrate by his other arm, rising to a height far above your own, cradled in his hold, securely pressed against his chest. Your hand weakly grasped at the hoodie you had made him, his everyday outfit nowadays.

“Sans, what-”

He rumbled in response, and somehow you recognized it as his own version of a shush – a particularly smarmy one, but with a softness that made it terribly effective.

With very little ceremony but an almost suprising amount of care, he set you down in your preferred section of your blanket nest, ignoring your vague half-hearted noises of protest. As he stood, a flick of his tail flopped your favorite blanket over your head. By the time you managed to coordinate your exhausted limbs enough to pull it off you with a poor attempt at a glare, he was flopping back onto his own nest of blankets, a large, fresh notebook zipping over to him, colored in his blue magic.

***i need to take down a pretty substantial amount of notes, sweetheart, so hit up snoozetown for a bit.**

Your eyes narrowed at him, your exhaustion making the majority of you all too amenable to his suggestion... but a part of you protested regardless.

“I can do it,” you mumbled, even as your eyes started to close.

***nothin' to do yet. get some sleep, we'll get into the weeds when you wake up.**

You huffed a sigh, but your will to protest was thoroughly defeated.

As sleep claimed you a scant minute later, you distantly wondered what the warm feeling was in your chest after that, and if you'd remember to ask Sans about it when you woke up.

 

\------------------------------------------------------

> **January 19, 201X**

You stared at the panel, your body stock still beside Sans. Your hands were curled around your notepad, your lengthening hair pulled into a messy gathering to keep out of your eyes. Sans stood similarly still next to you, his claws hovering at the ready over the panel. Deep shadows lined both of your eyes.

… Two and a half days with no proper sleep was a long time to chase a lead.

Magical energy, its flitting, humming, lively presence now becoming a familiar sensation to you - something that had apparently  _ always _ been there, at least once monsters had returned to the Surface, but you had no experience or awareness to tune into it - that energy washed through the room in agitated waves. You both stared at the machine, new paneling replacing old, several new series of tubes and careful rewirings and even a new alternative cooling system comprising just some of its updates.

A red light flickered on in the panel. Your and Sans’ breath caught in your chests, anticipation growing, nearly choking the room-

It began blinking on and off in a steady beat.

You and Sans let out a shout of relief and excitement at the same time, you jumping towards him and shaking his forearm in your excitement, only tearing your eyes away from the panel after another few seconds of willing yourself to recognize that this wasn’t just a fever dream. Sans’ other arm had lifted and he was dragging his hand over the crest of his skull, the shadows under his eyesockets still heavy, but relief and hope lightening his expression for the first time in so long - something you had a feeling was mirrored in your face.

“Sans,” you simply said, too many words and so much nervous hope in your voice.

He nodded slowly, almost dazed, his gaze turning down to you.

***it’s back to where it was - or… fuck,** **_better_ ** **,** he swore, exhaustion chased away so briefly by this.  ***we have to wait for at least a full day, then fully observe for a couple days, and further tests after that, but…**

“Holy shit, we halfway did it. I think I might love that little light,” you said, a grin spreading over your face even as that familiar sorrowful ache picked up in your chest. Exhaustion and the milestone dulled it, though, and you found yourself beaming up at Sans. “ _ You _ did it, Sans,” you emphasized.

A blur of blue flowed over his skull and he chuckled, strained, but shook his head and lifted a brow ridge at you.  ***shouldn’t have t’say at this point that i wouldn’t have been able to get this far without your help - certainly not like this, or this… well, doesn’t seem like it, but this** **_fast_ ** .

With just how infinitely you both were constantly focused on this machine and this work, even when taking care of peripheral tasks or trying to regain some mental stability in your occasional walks, you now at least had an inkling of what he meant. 

Before you could say so, though, Sans jolted slightly. You looked up at him, only vaguely remembering that your hand still held onto his arm.

***damn, got distracted when we fell down this rabbit hole a couple days ago, forgot that i had finished it-** he said, not quite addressing you even as his gaze briefly flashed to you.  ***hold on a minute, ‘ve got - or tell y’what, lemme just-**

About as cohesive as you were at this point, his words jumbling together even more than his laidback cadence usually had him speaking, magic briefly flashed in his eyelight and you found yourself carefully lifted and deposited on the edge of his blanket nest. 

Frankly, you were too tired to form a comment or a protest, or even fully register the fact that this was probably the first time you were ever really seated in his area. Instead you settled with making another noise of confusion at his briefly retreating back.

His magic flared again, and pulled a small box from the higher reaches of the shelves, stuffed largely with boxes and miscellaneous mechanical supplies that you both rarely needed and wasn’t pertinent for you to be able to reach easily. He snagged it from the air with flippant ease, and you were prevented from seeing what was in the box that he lazily tossed to feed the nearby trash tornado - which happened to be anchored to a single position in the room in the past few months. 

He turned back to you then, a tired grin on his face as his eyelights searched your face.

***ta-da,** he said simply.

In his hands was a small boombox, apparently modified with handiwork that was fully recognizable as his own. It featured a prominent tapedeck, and in between the digits of one of his hands were a couple of different tapes.

“... No way,” you whispered.

His grin spread wider, and he walked towards you.

***way,** he replied. He plopped down on his enormous blanket bed next to you, still carefully supporting the stereo.  ***took me ages to get it done with everything else going on, and a bit longer to find tapes that weren’t too wrecked to salvage… hope y’ don’t mind a pretty substantial amount of 80’s jams,** he added, almost as an afterthought.

“... I haven’t heard music in half a year, I’m pretty sure I’d be down to listen to the Hamster Dance on repeat at this point,” you managed to say. Despite your words, though… you finally tore your eyes away from the boombox, catching his gaze. “Sans, seriously, I- I’m so excited, I don’t think I can… You - you fixed this up? Made it? For me…?”

He shrugged, glancing down and slipping a tape into the deck before placing it on the ground in front of you, a hand going up to rub at  his neck afterwards, his grin still spread as wide as he could muster with the exhaustion.  ***you always bring up music, and i hear you humming pretty frequently when y’think i’m not paying attention,** he said. You blushed at that, both mortified and weirdly flattered.  ***so… i found some of the pieces for it, and figured i’d put something together.**

What the hell were you even supposed to say to something like that…?

He leaned forward, his claw tapping the play button.

A few moments passed, and then the warm static of the recording picked up, and a few moments later, the intro of the song kicked in. 

“Holy shit,” you simply said, unable to find the means to be eloquent. Your heart - no, your  _ soul _ swelled at that moment, and tears welled at the corner of your eyes.

***... seconded,** Sans said, his own eyes going wide. You had known that he liked music to at least some degree - it had briefly come up, usually when you were talking about an artist you enjoyed when something reminded you of their lyrics...

… Maybe it was the day, maybe it was the machine finally humming with tentative life a half a year later, maybe it was the synthy bass crackling warmly from the speakers, but all of a sudden, exhaustion and relieved joy hit you so hard that you laughed - and you didn’t stop. Sans’ skull turned towards you, confusion and vague amusement at your sudden apparent loss of a grip clear on his expression, but as you simply waved, gesturing to the stereo, and the machine, and the room, with no clear definition, Then he started chuckling too - and in seconds, you both were laughing so hard that you fell back, your tears flowing as his eyesockets screwed shut.

The song had nearly ended by the time you got a grip on yourselves. You took gasping breaths, situated deeply in the blankets, unable and unwilling to move. Sans was still chuckling, one hand resting over his chest, the other somewhere above your head’s position at his outstretched arm.

***so ‘m guessing you like it, then?**

The song faded out, the next one picking up just as quickly, a beautifully absurd drum solo leading the way into the jam of an intro.

“I fucking love it, Sans.”

You both laid quietly in his blanket nest, the song washing over you both as your focus broadened and relaxed, born on the cresting audio.

You woke up the next day, far deeper in the thick and comfortably supportive tangle of blankets and enormous pillows. One of Sans’ arms was draped over your waist as his form spooned lightly around you, his tail completing a loose, protective circle around your form.

… You rolled over, facing him now as you shifted slightly closer to him. The machine continued to hum quietly in the corner as you let sleep take you once again.

\------------------------------------------------------

> **March 21, 201X**

The red light on the panel blink off and on, off and on, not yet failing in its steady beat since the two of you had managed to get it running again.

“I swear that shit is mocking us.”

You sat on top of a portion of the workbench closest to it, your head in your hands, your voice flat.

***you always say that.**

Sans sat near you, his gaze on his notes. His voice was just as flat.

The majority of the cabin was covered in new and old pages of notes and opened notebooks and referenced books, barely a trail to walk between them. Organized chaos, born of your growing frustrations, and each day feeling more and more like an accurate representation the tangle of half-finished theories and close-but-not-close-enough conjectures crowding your mind.

“I’m always right about it.”

Sans ran a hand over the crest of his skull. His bones clacked lightly against one another, a sound that had become such a standard as to become comforting, a sound denoting what was often a moment of commiseration or shared stress, where you knew that if nothing else, you weren’t alone-

***... let’s take a breather.**

Right now, something about it was just…. pouring salt in a pissed-off wound.

“Feels like we might as well have been taking one for the past two months,” you bit out. “Not like we’ve gotten any damn where for all our fucking headaches.”

On, and off. On, and off. 

It reminded you distantly of a wifi router when you were having a sleepless night, the light so unobtrusive it shouldn’t make a damn difference, but somehow driving a barb into your awareness nevertheless.

***welcome to fucking science** , Sans grumbled.  ***progress is measured more in figuring out what theories are bullshit than in what one’s** **_aren’t_ ** **.**

“Fuck progress,” you said bitterly, your eyes not moving from the machine. “I just want my fucking sister back so this shit can be over.”

Sans was quiet.

The machine hummed in the background, it’s constant magical energy brushing over your awareness. It felt like infinitely long than the few months that had passed since you had first seen your soul - you were now terribly acquainted with it, no longer feeling quite so strongly as if you were cast in a raging sea when it was out, but Sans had so far been unable to create a stable container to store any samples from your soul. It was making further study nearly impossible, as he refused to have your soul out for any extended time, and would only take it out for once a day. He dodged your ever-increasing questions on it as he dodged everything else.

“... Fine. Fine! Let’s break. Whatever.”

You slid off the desk, the practiced ease with which you navigated the tiny openings between books and papers only serving to cause you to grind your teeth.

Your hands snatched up your leather jacket too aggressively, and you quickly began to shove your feet into your boots.

***... we should eat.**

His words were a tired echo of the very phrase you had been saying so frequently lately. You barely kept track of the days as is - the habit becoming more of a ritual than a necessity, given how little meaning the passage of time had down here, and how probable it was that you didn’t have anything waiting on the surface for you anyways - with whatever the new fucking cursed barrier had done when you fell…

“I don’t feel like it,” you said shortly, moving to stand.

Sans shrugged.  ***neither do i. But…**

“But nothing, Sans, I’m not fucking up to it right now,” you bit out, your posture rigid, your hand on the door. “If you wanna eat, be my guest. I need some fresh air.”

He didn’t look up, but you were too familiar with the rigid line of his spine, the tightness of his jaw.

***yeah, good luck with that. let me know if you find any.**

“Least it won’t be as fucking stifling as this room.” You were already half out the door. Sure enough, the cold air rushed to fill in the room, but it was anything but  _ fresh _ .

***** **_snow_ ** **problem, not when** **_icy_ ** **your attitude is frigid enough to make it not matter,** Sans muttered.

Your head snapped back to him.

“You wanna run that by me fucking again?”

***whatever.**

You took a half-step back in.

“No, you - what, my attitude isn’t exactly  _ savory,  _ is it? Not  _ cheery _ enough, eight months into fucking all of this, barely just at what we  _ should have _ started with, and fucking dead stalled for two months?” 

Icy? He thought your previous attitude was icy?

***just go on your damn walk,** he said. You could see the grit of his sharp teeth. Everything reasonable in you was telling you to stop, to go clear your head, but you were feeling less and less attached to those parts of you. 

“I’ll do what I damn well want,” you shot back. 

What fucking play did _reason_ have in any of this, anyways - in any of _anything_ _at fucking all?_

***don’t i know it** , he shot back. His hand twitched on his notebook.

“You’re one to talk-”

***oh, you’re right, what do** **_i_ ** **know of your fucking struggle-**

“Don’t fucking flip it like that, you know what I mean-”

***do i?**

“Fucking- could you just be less of an ass, for  _ once _ !”

***can’t get less of an ass than i already have,** **_sweetheart_ ** **-**

“I swear to- you’ve got enough of one for me to kick into next week, you dick-”

***yeah,** **_real_ ** **creative there, i’m shaking, ooo, listen to my bones fucking rattle-**

“Just fucking drop it, okay?!”

***never thought i was the one holding anything to even drop, here.**

“You  _ hold  _ ALL the damn cards, Sans, fucking always!”

Sans’ notebook snapped shut.

***that’s where you’re wrong,** he muttered.

“Sure doesn’t seem like it to me!” You threw your hands in the air, the door still ajar behind you.

***you don’t know what you’re talking about,** he growled, still not looking at you.

“Oh, wow, it’s almost like I’m completely in over my head!” You gasped sardonically. “Like I had to try to fucking grasp a branch of science that fucking astrophysicists would struggle with, while stuck in a cave, my sister fucked off by some stupid machine into non-space-time, digging for scraps of food while feeling more inadequate by the goddamn day, only to one day figure out that  _ nobody else fucking even remembers that she existed _ , and that they at best think I fucking  _ died _ -”

***you’ve been at this for 8 months, that’s - that’s** **_it-_ **

“Your own goddamn fucked up life doesn’t make mine any less fucking shitty, or these circumstances more  _ wildly fucking uncalled for _ -”

***you think i fucking** **_wanted_ ** **this, any of this?**

“That’s not what I- don’t twist my words, dammit-”

***enlighten me, oh great human! what** **_did_ ** **you mean?** Sans’ eyelights cut to you at last, his words cutting, his eyelights pinpricks in his sockets. His hand shook, just barely visible in his hold on his notebook.

Your face burned, your eyes watering traitorously, tightness burning through your chest, closing up your throat.

“I - we’re just-” you tried furiously to blink away the tears, fury burning hot through you, almost as hot as the hopeless frustration lashing out in your soul. “I’m allowed to fucking-  _ agh!” _

You spun on your heel and left, the door slamming with more force than you intended behind you as you took off in the snow, your chest heaving as you ran.

Choking on a sob, you let your feet carry you through the biting chill and into the foggy warmth of the entrance to Waterfall. You didn’t slow take your jacket off, the mere thought of stopping for even moment pushing you harder.

How much better off were you than your sister right now, really? Stuck in a glorified hole, digging through trash every day, feeling horrifyingly relieved just to have warm water most of the time, pulling your hair out day after day with science that only made you feel like you knew less the more time passed, stuck in the company of a guy whose mind on the matter was unapproachably beyond your own understanding, but his deeper attitude and his ability to keep plugging away at it when if anyone  _ would _ know the answer, it  _ should _ be him, but here you were,  _ here you fucking were- _

Your heart panged in disgust at your own distress, a treacherous part of you pulsing sickeningly, reminding you that monsters had been trapped down here for centuries, and here you were, sick of it after comparatively so little time, bemoaning it all, while your sister was probably in some faceless eldritch of a dimension-

Your feet caught on a patch of rocks and you hit the ground, hard, biting off a  cry as blood pricked through cut skin. Pushing up quickly though, you just kept running, desperately ignoring the burning in your legs and lungs, trying desperately to flee your own thoughts, your own feelings, even the part of you that tried to whisper that it made sense for you to feel this way, that you were  _ allowed _ to be frustrated and upset, that even if things had gotten too heated earlier, you were right at least in that other’s suffering didn’t negate your own struggles-

You dropped to your knees finally in a damp patch of moss, echo flowers nearby, glowing water directly in front of you. Your lungs were on fire, and you clawed at your chest as you curled up, breath not coming to you, nothing to power you through further movement. Bile rose in your throat as pain ripped through you, just as real as the pain in your cut hands.

Choking out a sob, your eyes screwed shut.

Your body heaved as the tears spilled down your cheeks, nothing but the sound of distant running water accompanying the muffled sounds shaking from you as you clutched your arms and fell apart, completely alone in the isolation of the caves.

**Notes for the Chapter:**

> ... you were bound to snap, eventually...
> 
> ... after all, it's only _human_...
> 
> ... right?


	4. Closer Yet

**Summary for the Chapter:**

> (... Merry Gyftmas. We now resume our irregularly scheduled skeleton-loving content.)

**March 22,  201X**

Your calf dangled in the pleasantly cool glowing water, so near Hotland that you had shrugged off your jacket and rolled up your pants long ago. Your chest ached, but it was a distant feeling now. You had long since cried yourself out, and had to detour to grab water and snacks from one of the stowaway points you had found months ago when out wandering with-

You cut your thought off fiercely, not letting yourself think about him again yet.

The night had been a long one.

Focusing vaguely on precisely nothing at all, you tried to let yourself just  _ be  _ in the numb feeling you were experiencing after the long night. The water your leg made gentle ripples in was mesmerizing in a gentle way, and the mossy grass you sat on was soft and had made the scant couple of hours of sleep you had fallen into more comfortable than you would've guessed.

You were still sore, though.

A huff left you, noting the double implication all too well. Yes, your muscles were sore from the odd sleeping place, but your heart was, too. Or, rather, your soul was. Your hand went to your sternum, a frown pulling at your expression as you tried to sense it within your chest.

It had been... god, nearly three full months since... he... had pulled out your soul for that first time. It had taken nearly a week for you to get him to do it again - it was frankly impressive how many 'backend theories and tests' he had come up with in the meantime to put it off, for some reason he still hadn't explained to you - but since then it had become something you both had done nearly every other day. He hadn't spoken aloud while your soul was out since that first time, though, simply listening while you described the sensations, and he appeared to take measurements with an increasing array of tools and processes that he was exceedingly careful to never let actually touch your soul.

Despite your numbly lingering emotional upset, heat rose to your cheeks. You had quickly figured out that having your soul out made every one of your emotions more visceral and clear, and you weren't so blinded by your frustration that you didn't notice how much... warmer your feelings had become towards him. And then on the occasions his hand had strayed close enough to your soul after drawing it out - usually to try and take some sort of specific measurement, even if he didn't have a way to draw or store samples for inspection - you could feel just a hint of  _ his  _ feelings.

... Well, what few he didn't manage to keep under a pretty incredible lock and key. 

But it was odd - something in the magic of your very soul seemed to make reading him all the easier. And when he did stray close, you could snag fascinating glimpses of his emotions. Fascination, focus, intrigue, hope - and then others, on the bad days for you both, where frustration, guilt, hopelessness... they would win out.

Your own feelings often weren't a far cry from his, as in sync as you two had become over the many months.

Your hand absently brushed and buried into the moss near your thigh as your gaze roved over the echo flowers sprouting from the mossy banks across the stream.

Sure, your anger had faded. It was bound to - you never felt like you had the energy to keep it up down here, not after the first couple months. Let alone at him - at Sans. He'd always end up finally swinging some shitty joke that made you laugh despite yourself, or he'd bring some new observation or theory to your attention, drawing your attention away until by the time you remembered you had been mad, it had faded and felt a little pointless - because in the end, it always was. It was rarely about him - not anymore. The first few months he certainly hadn't made it easy to like him, with his lowkey antagonizing, admittedly teasing ways - but at the same time... you hadn't been much better.

It had been too easy to blame him, hadn't it? On the one hand, he did sort of kidnap your sister... but he had also saved her from certain hypothermia, hadn't he? And considering he had been alone down here for at least, what, five years... it was a little too easy to empathize with his attitude and insistence for it. Plus, maybe he had been considerably gentler with her before you had busted in, literally wielding a branch with intent to kick some ass in whatever way necessary -

You scoffed slightly at that thought, a small smile tugging at your lips. He was a little too smarmy to be outright gentle, probably. And his reaction to you - well, you had a feeling the last thing he was expecting was a pissed off older sister threatening him with a damn branch.

So yes, you were... maybe both a little at fault for the tension for that first while. Especially with the broken machine. Yet... after that, you had genuinely started becoming close. part of it was natural - for heaven's sake, you spent almost every waking minute with the monster, outside of your individual wanderings when you needed space or to stretch your legs - but part of it was... well, you just clicked. His humor well matched your own, and the teasing rise you had started to so easily be able to get out of one another was something you couldn't help but look forward too. You'd be lying, too, if you weren't drawn to the way he could get so deep into his theories and scientific thoughts - he wouldn't always ramble with it, but that deep concentration, the careful movements of his claws as he handled and built new equipment, or made thorough adjustments on old pieces - or would somehow find ways to explain in complete layman's terms the most convoluted of principles so that you could get a better understanding of what the hell you both were doing, to the point that you were actually pretty proud of how much you knew on magical engineering and what amounted to quantum physics, more certainly than you might have even with a college degree in either subject-

Because that's just how thorough Sans was.

You sighed now, your head falling forward to rest on your raised knee.

... Really, that's why your fight yesterday had hurt so much.

Sans wasn't just a companion, a necessary part of the only way you had to get your sister back - he was your friend. One so close to you now that... even if you hadn't fully opened up about all the details of your life, you knew you trusted him enough to share that with him, should you decide you wanted to. One that knew your quirks and humor and preferences so well that he'd often think to address them before you had the chance to. And it was the same for you to him, too - catching his oddities in where he'd leave his notebooks, knowing which band’s tape to slot into the stereo he had built for what mood he was falling into, hell - even knowing when to try a knock-knock joke on him as opposed to a general situational pun.

The pressure built up in your chest again, verging on breaking through the numbness you had fallen into.

Dammit, you had just needed space. You didn't know how to handle the building frustration after stalling out on measurable progress for so long, the hopelessness that was starting to drag at you building too heavily-

-and you had effectively tossed his own feelings out the window in the process.

You groaned into your knee, the sound quiet but too loud in the caves that only sounded with the soft echo of moving water and distant waterfalls. Fuck, you were allowed to be frustrated too, sure, but how the hell did you navigate that when, well... he had been through so much of the same-? Desperately you found yourself wishing he had just let you go on your walk, rather than - than,  _ fuck _ , just trying to get you to eat something since you hadn't in... probably twelve hours, at least, with how long you both had been working.

… Shit.

Your frustration lingered, but you had burned yourself out of anything hotter or darker than that. Your leg stilled in the water, your fingers buried out of sight in the moss, and your eyes closed as your soul ached distantly. 

What really was there to do, but either give up entirely, or just... keep plugging away at the machine, when no hope existed down here but whatever you built for yourself?

Your thoughts went quiet and vague for a few minutes. Softly, you started to hum, your chest easing a fraction as the lyrics came to you, and you found yourself singing softly, almost under your breath.

_ "There's no sunshine, this impossible year… _ _   
_ _ Only black days and sky grey, and clouds full of fear. _ _   
_ _ And storms full of sorrow, that won't disappear, _ _   
_ __ Just typhoons and monsoons, this impossible year..."

***... mind if i join ya?**

You nearly choked in surprise, and the leg you had propped up with your foot at the edge of the bank slipped and sent your leg splashing into the water.

***whoa, there, sweet- i mean, er - sorry, didn’t mean to…**

You looked up, coughing slightly as you grimaced at your now soaked pant legs. Sans stood a little ways behind you, clearly having stopped short to give you space. In just the night you had spent away - the  _ first night _ , your mind whispered to you in sudden vague realization of the fact that you had now slept in the same room as this skeletal monster for the better part of 8 months - you had somehow almost forgotten his size, or your memory just - clearly wasn’t inclined to do him justice. 

His hands were buried in the large pocket of his hoodie, and his worse-for-wear shorts looked particularly… ragged, as if he hadn’t stopped moving out and about for far too many hours. The slight twitch of motion in his hoodie pocket was a sure sign that he was clenching and unclenching his hands, something you had noticed he’d do when particularly agitated or unsure…

His skull was angled off to the side, but his eyelights were warily settled on you. The dark shadows under his eyesockets were even deeper.

Absently, you lifted a hand to the shadow that had grown under your own eyes. 

Seemed like you had ever more in common with Sans than you guessed.

You sighed quietly, a corner of your mouth upturning just the slightest measure. 

“It’s fine. Yeah, come, uh… take a seat.”

You pat the moss beside you and turned back to the water. Somehow, you couldn’t quite bear to watch him at the moment.

A moment or two passed, and then you felt the shadow of his bulk approach. He paused at the bank, but you just kicked lightly at the water both your legs now laid submerged in. He lowered himself slowly, his legs crossing in that strangely lithe way he could move when he wasn’t being lazy, and his tail swept to his side opposite you. His back was curved more than usual, and from what you could tell out of the corner of your eye, he wasn’t looking directly at you - instead opting to stare into the waters, as you did.

You both sat there for a minute, nothing but the sound of slowly moving water and distant waterfalls shared between you. Only the ambient glow of the streams and the echoflowers and scattered crystals provided light.

Your very soul felt… subdued.

***this isn’t the first time i‘ve had to rebuild the machine.**

Sans words startled you out of your reverie, enough for your eyes to flicker towards him. He still stared forward, his hands buried in his hoodie pocket.

***i… had the gist of the machine built already when the second barrier went up, actually. though with the way life’d been going… i had given up on it for a long time by then,** he admitted, his voice too rough.  **hard to get into why, but at least before the first barrier broke, i had… there were others around. the rest of monsterkind. my brother had been erased for years by then, and the work i’d been doing had to be in secret and… well, wasn’t panning out, obviously. so i focused on just tryin’ to make it through each day with the only family i had left- my other brother, the youngest of us three. us two, at that point, effectively.**

His breath huffed out of him, a self-deprecating sound coming with it. Part of you wanted to comfort him, but… you stayed quiet, waiting.

His tail shifted slightly, the tip stirring the glowing water in front of you both.

***... after a while, once i fully accepted that i was stuck alone down here, i… eventually started working on it again. never got it fully operational obviously, though lookin’ back i know now i was closer than i thought - anyways, after a lot of denial, some bargaining, a hell of a lot of cursing… i may have… broken it. a lot.** He grimaced, and his head angled slightly away from you. He looked... ashamed.  ***it just… i have a lot of patience, but being down here… it gets to you. worse when you’re alone, but… i can’t exactly blame** **_anyone_ ** **for feelin’ similarly, regardless of the amount of company.**

You let out a breath you hadn’t even realized you’d been holding.

“Sans, I…” you frowned, your chest aching as you tried to figure out where to even start. “It’s not… it’s not  _ you _ , not really - it’s just…”

You exhaled sharply. The words weren’t coming to you. What  _ could _ you say, that wasn’t glaringly obvious?

He cut you off with a slight shake of his head before you could gather yourself again.

***it’s not somethin’ you have to explain - i get it a hell of a lot better than most people would. the frustration, the guilt, the anger, the focus, the weird kinda almost-hope, hell, even that sliver of pride when it seems like something,** **_something_ ** **is goin’ right-** his back began to straighten slightly, his voice still rough, but stronger,  **-and then, then it just goes and fucks up. because that’s life, but stars it feels so much** **_worse_ ** **down here. ‘specially when… a lot’s riding on what you’re workin’ on.**

At last, he slanted his head towards you. You had to tilt your head pretty far back to meet his gaze, but his slouch made it easier. A moment passed like that, his eyelights on you, you remaining quiet, not sure where to go forward, or if he’d say more, but  _ hoping _ he’d say more.

***... i wish it was me in there, and my bro out here,** he continued quietly.

At that, your heart skipped a beat. 

… How many times now had you had that same stray thought about you and your own sister cross your mind? No matter how quickly you tried to stamp it out it’d come back eventually. She rarely got outright angry about anything, but you knew your sister too well to not acknowledge that she’d be well on her way towards becoming far more than frustrated if she knew you wished that. But at least then  _ she’d  _ be free, and safe to some degree - screw yourself, at this point -

… And hell, you even thought… maybe it would be easier, in some terrible way, to be outright  _ trapped _ , with nothing to do about it… as opposed to trapped  _ with  _ an incredibly daunting  _ something  _ to do about it.

You frowned at yourself, and at the mirrored emotions you could see running through Sans.

“... You can’t think like that,” you said quietly. His gaze didn’t turn back to you, but you knew he had focused on your words. “Or… you can,” you said, a dry, wrung-out sound to what was attempted amusement in your tone. “But… you can’t let yourself linger on it. I know that exact thought, but… they wouldn’t want us swapped, and I think you know that.”

He was regarding you with an expression you couldn’t quite read. 

*** they really are similar,** he said. Your brow lifted lightly in question, and he chuffed.  *** my bro ‘n your sis. well, from what i know, anyways,** he admitted, glancing to the side. 

In the end, despite the fact that you both were working nearly ceaselessly to get them back. There had always been some unspoken line that neither of you crossed, as if talking about them would make their absence feel too… real. Hearing this much from him had your attention entirely.

He continued after a moment, though, his focus on the middle-distance.  *** i never told you about meeting her, did i?** The question was rhetorical - you both knew he hadn’t. He paused though, as if hesitating.

Your body shifted, letting your posture open a little more to him, curious -  _ wanting _ to know. There was an ache at the thought, but… “Tell me?” You prompted.

He remained quiet for a few seconds, but then he huffed, a sound close to a laugh.  *** for someone so inclined to believin’ the best in a person, she’s feisty, isn’t she?**

That startled a laugh out of you. “Oh my god, what did she do?”

His maw was curved, a vague grin on his face in memory.  *** i was walking through Snowdin when somethin’ droppin’ from the cavern ceiling caught my eye - cursing up a** **_storm_ ** **i could hear even that far away before it suddenly cut off. i won’t lie, i was expectin’ the worst when i got there… but there she was, only scraps of her hoodie over her shoulders and wearing just a damn tanktop underneath ‘n jeans to top it off - looking like she was deadset on politely but thoroughly cursing out the snow she was buried up to her waist in.**

He snorted as you choked back a laugh at the mental image, your soul throbbing in your chest. You could picture it a little too well. 

*** she sees me then, goes real quiet, and then in a resigned voice jokes somethin’ about ‘listen, if you’re some kind of casual-Friday reaper, can you make it quick? i can’t feel my toes and i’m pretty sure my ass is so frozen it’d put a diamond to shame, and the only way i’m gonna put up a fight is if it’ll bring me quicker to that warm light everyone talks such a big game about.’**

Your hand was over your mouth, not doubting the thought of her casual sassing of a 12 foot tall skeleton monster. When she was done, she was  _ done _ , but had a weirdly cavalier attitude about it. It both hurt and warmed your soul to hear this, and you didn’t look away from Sans as his eyelights refocused on you.

*** i asked her that if she wasn’t** **_toe-tally_ ** **resigned to gettin’ scythed by some other wanderin’ halloween decoration, if she’d be willing to help me with a machine i’d been workin’ on. told her there was a warm cabin in it for her, and a chance to get some** **_ass_ ** **-istance in gettin’ some answers.** He grinned unapologetically at that, and you couldn’t help but lightly swat at him, breaking the invisible line that had been drawn between you. He shrugged, admitting with that grin still in place,  *** my social skills were a little rusty, what can i say. plus i wasn’t entirely convinced i wasn’t hallucinatin’ her regardless, so y’know - ‘n hey, her** **_agreein’_ ** **to go with me at just that much only added to that feelin’.**

“... Alright, yeah, I can’t blame you there,” you admitted in turn, your grin twisting in acknowledgement. Having been down her with him for 8 months now… he had been alone for over five years? Hard not to second guess seeing someone else so suddenly, you couldn’t help but agree.

*** so i pretty unceremoniously scooped her out of the bank she was in, set her on her feet, and told her to follow me - she didn’t make it far before fallin’ though, so after she was done bein’ weirdly polite ‘n refusin’ me pickin’ her up, i, uh, picked her up,** he shrugged, as if that was logical. You shook your head - too able to picture her refusing to ‘trouble someone’ for help even on the edge of hypothermia.  *** carried her back home quick enough, ‘n once we got inside she just… face planted into my sleeping area.** He looked amused and baffled, even more so at the look on your so.

“Yeah, hell, she must have been freezing by then - did she bury herself in a blanket burrito, by any chance-?”

He nodded, his hand going up to his head, clacking lightly as it ran over the surface.

The sound was… reassuring, now. 

*** i swear, i thought i broke the human. i just guessed at shit and gave her some hot sea tea from my stash and kept pokin’ her, figurin’ from what i’d read about humans that her sleepin’ right away wouldn’t be good. next thing i know she’s perkin’ up after managin’ to drain the tea, ‘n stumbled outta that blanket burrito ‘n was huggin’ me-**

“Oh, the terror,” you interjected, dryly teasing at the lost way he shook his head. He snorted at your sass, rolling his eyelights before eyeing you with a lopsided grin. 

*** don’tcha mean ‘** ** _oh, the humanity’?_** He intoned with a wag of his brow, marking it your turn to roll your eyes despite your grin. *** anyways, she then swore she’d figure out a way to help me, once i got around to mentioning i needed to observe her soul ‘n test some shit to try ‘n get my bro back. that was what got through to her more than anything, ‘specially since i wasn’t quite as** ** _cuddly_** **at that point.**

He was looking at you oddly now, his expression between dry amusement and… something softer. It made it hard to look away… so you didn’t.

Finally he continued, his voice quieter.  *** she said she had to get back to her sister. even though i told her while carryin’ her back to the cabin that it’d be impossible at least any time soon, and that within a day the barrier’d have her forgotten anyways, she just… shook her head, grinned up at me, and told me that there was a way, even if i hadn’t found it yet - ‘n she’d make sure i got my bro back, first, because three knuckleheads were better than two, ‘n what was a ‘shitty magic spell’ in the face of the kinda love good siblings had between ‘em.**

He fell silent, not looking away from you.

Your eyes felt hot, and your chest tight.

… Still, even with your expression twisted and the wetness pooling at the corners at your eyes, you smiled.

“She always was too damn nice for her own good,” you said, voice quiet and strained.

Your face fell, your eyes closing as you tried to swallow back the emotion welling in you. The only sound for a long time was the soft flowing of the water through the cave, and the distant sound of larger waterfalls. 

Your eyes only opened when you felt something against the hand you had buried in the moss. The sensations shifted, and you realized immediately - it was Sans’ hand, effectively dwarfing your own, tentatively resting over yours.

You looked up, unfallen tears catching the glow of the cave as you found him looking down at you - a slight tinge of magic on his cheeks, but deep, sorrowful empathy in his expression like you hadn’t seen before.

*** we’ll get her back,** he said, quietly.  *** whatever it takes, we’ll find a way.**

Your breath was caught in your chest, your cheeks flushed - though whether from your near-crying or… something else, you couldn’t quite say. Your hand slowly shifted beneath his, threading your fingers through his grip, feeling so small in comparison, but… safe.

“We’ll get them  _ both _ back.”

Your head fell to the sturdy line of his arm, resting against him. For the briefest second, you felt him go tense - but he relaxed just as quickly, almost making you wonder if you had imagined it.

*** … yeah. we will.**

“... Sans?”

*** yeah?**

“... I’m sorry.”

*** … i’m sorry too, sweetheart.**

You stayed there like that with him for a long time, resting against him as the water flowed tranquilly around your legs. At some point, you felt his head dip down, the tip of his skull’s snout brushing against your locks - but you couldn’t help but wonder later if you had dreamed it, as it wasn’t long after your memory faded, only briefly supplying you with enough awareness to know you had woken up briefly in his arms as he carried you through the caverns, nestled close to his broad chest like something treasured.

 

 

* * *

 

**May 19, 201X**

You cracked your back as you stretched upwards on your toes, a satisfied sigh rolling through you as you settled back down, your hands going to your hips. 

*** i swear, it’s** **_gotta_ ** **be against those geneva conventions i read about to make sounds with your spine like that.**

You grinned at Sans as he rose from behind the machine, his hoodie sleeves pushed over his elbows and a sautering tool in his hand. He ran the back of his free hand over his skull, a fine sheen of magic wiped away from his forehead as he did so.

“You  _ wish  _ you could crack your back like this, bone boy,” you shot back, continuing to stretch other parts of you after having been crouched for so long. 

*** seeing as for** **_me_ ** **that would imply significant greater injury that whatever weird joint… gaps you humans get, i’m gonna solidly deny that accusation.**

You snickered at the exaggerated roll of his eyes as he stepped away from the machine to put up his tools. Despite his words he too stretched, though without the sounds - minus a small, subtle purr of satisfaction in the motion.

It had been roughly two months since you had fought, but honestly - it felt like that snap in tension had been truly cathartic. You and Sans were communicating more openly now and had grown closer because of it - he hid fewer things from you, and you both had opened up about your relationship with your lost siblings, too, which had been healing in other ways.

“I think we’re finally inching the machine’s progress past the point that it had been at when I fell down here, right?” you ventured as you completed your stretches, torn between what to tackle next. 

Sans shook his head, nearly making you frown, but he grinned at you instead, lifting his brow.

*** not exactly - i’d say we’re** **_further_ ** **, sweetheart. you’ve caught a lot of little things i’d made mistakes regardin’ the first time through - so while we look to be at a similar place, i’d lean towards several steps beyond.**

You idly played with the bracelet you had made long ago now from the scraps of your sister’s hoodie, your brow raising at him. Despite his grin you could only feel genuine intent behind his words, and your cheeks tinted slightly as you glanced away, playing it off.

“Oh, hardly - you caught whatever it was, I’m sure, I’m just a sounding board,” you said, waving him off. “One who puts up better than the walls with your bad puns.”

*** you love my bad puns - no** ** _bones_** **about it,** he shot back, his grin only growing as you scoffed but were unable to hide your smile. *** ‘n besides, you did a lot more’n that. you’ve been workin’ hard,** he said plainly, his own brow arching right back at you as he ambled closer. *** literally every day. that adds up to a hell of a lot more practical experience and know-how than more graduate college students could dream of gettin’.** **you’re as capable as any lab assistant, if not more so - after all, you’re willin’ to call me out when i’m gettin’ ahead of myself.**

You were more than a little flustered now, though you continued to try to play it off, shoving playfully at his arm. He was so large he didn’t even budge, and instead his tail swung up and swept one of your feet to the side just enough to make you stumble for your trouble, making him chuckle at the spark in your eye when you threw him a look.  “You’re just eager as hell to fall down a rabbit hole and I don’t have a paycheck to lose for pointing out your tangents,” you replied, refinding your balance as he strode idly past you then, his tail brushing over the floor, just shy of disturbing some of the notes and diagrams spread out. 

*** seein’ as** **_you’re_ ** **the one that fell in the rabbit hole, that’s pretty rich,** he teased back, his grin shit-eating as he fell back into his mass of pillows and blankets. 

You snorted at that, crossing your arms. “Alright, you got me there. But still,” you shot back vaguely, just making him chuckle again. You gave up, recognizing he wasn’t going to relent on the offered praise, and took it reluctantly - with an odd sort of thrum in your soul. 

Your hand shifted absently over your sternum as you glanced back at him - his arm had dove into his raised pillow nest, drawing your confused look. He simply waved you over, digging around for something.

“So what’s next, big guy?” You asked, coming to a stop in front of him, your toes nudging at the tail end of a blanket as you cocked your head at him, uncertain what the next tests would be for the machine.

He seemed to strike gold then, his expression shifting to something pleased as he began to tug whatever he had grabbed out. 

*** next… we take a break.**

Your brows flew upward, shock in your expression. Unless the project was stalled or you were waiting on the results for something, there had been really no breaks - not something so explicitly taken, anyways, not at so positive a point. They were turned to usually out of necessity or too-far-gone frustration - your mutual drive and urgency pushing you both to the brink of collapse a few too many times now.

… Then again, maybe a positive sort of break wasn’t a bad idea…

You were having something of a mild face journey, making Sans chuff at your antics before his tail swept behind you and nudged you off balance, sending you toppling into his nest of pillows and blankets.

“Hey-!” you protested, pushing your face out of it’s new home to look up at him, only to cut off as you saw him drag nothing other than a literal trombone from the depths of the nest.

*** wanna guess what a skeleton’s favorite instrument is?** he said, his eyelights sparking with a kind of mischief you secretly delighted in, though you pretended otherwise - however poorly.

“Oh my  _ god _ ,” was your only reply as you rolled over in the pillows, about to try and push upwards when you felt his hand go to your shoulder, steadying you in a comfortably but confusingly still-seated position. 

*** you know how you were asking me the other day about my bro, ‘n what we were like when we worked together?**

“Of course,” you immediately responded, not sure where he was going with this.

Sans huffed in vague amusement, clearly catching your confusion.  *** i told you about how we both tended to get wrapped up in our projects, but balanced each other out surprisingly well despite it, yeah? that we’d pull each other’s attention enough for the mental breaks we desperately needed, and would manage to get each other to break to eat ‘n all that,** he prompted, getting a nod from you. His eyelights shifted to his trombone, settled easily in his grip.  *** we also took to, uh, pranking each other, heh. ‘specially when we were in frustratin’ stalls - helped with those mental breaks, ‘n the laughter ‘n shit would then turn us into takin’ a proper break - ‘n we’d often find ourselves headin’ back the next day with a new take on it, ‘n would even sometimes have a breakthrough.**

He shrugged, looking away, the clear wistful fondness he had for his brother seeping into his tone. You had realized a month ago that Sans hadn’t talked about his brother in a number of years he couldn’t count anymore - since no one else could remember him even when he  _ had  _ been around other monsters, there was no point, and so he had locked away all his memories of him deep within… explaining even more of his hesitance in talking previously about him. Now though, he had opened up more, and it seemed to do him a lot of good to peel away the old bandaging over the pain he had felt for so long.

“... So you picked up the trombone as a joke?” You said slowly, looping him carefully back in. He seemed to snap himself back into the moment, his grin returning as he looked at you.

*** you’re damn right** , he answered. You laughed at that, and finally rearranged yourself, settling in to his nest, feeling oddly at home there next to him. The trombone looked comically small in his large grip, but he still held it in a way that spoke of one hell of a practiced ease. 

“I’d say I can’t believe you’d teach yourself how to play an instrument solely for comedic effect but honestly I absolutely can,” you remarked, crossing your arms and looking up at him with a decidedly sassy tilt to your head. 

*** good to know i can still live up to my previously established reputation,** he said without an ounce of shame, lifting the trombone to his mouth. You almost wondered how the hell he’d play the thing when he didn’t have actual flesh - but a little too easily your mind supplied you with the way you’d long-since noticed his bone was malleable particularly in his skull, shifting to emote expressively and shifting his mouth beyond the closing and opening of his jaw, revealing or hiding more of his teeth as he did so. 

He blew into the horn comically horrendously once or twice, pulling away and feigning shaking it as if something had gotten stuck inside, before winking at you.  *** i won’t** **_toot my own horn_ ** **, sweetheart, i’m probably a little rusty,** he said - before promptly twirling the horn deftly in his claws and catching it smoothly, lifting it up to his mouth in a motion so practiced you didn’t believe him for a moment.

Then again, you hadn’t seen that thing the entire time you’d been here - some ten months now. If he was good with it even now, just how much had he played previously…?

Your musing was stopped in its tracks as he began to play. 

He eased into it, the auditory equivalent of stretching lithely after a long rest, sliding through notes, testing the sound, his eyelights brightening as he settled into the motions, something else coming alive in his bones and expression. It was like he was meeting an old friend, or diving into water for the first time in years after being raised by the sea - you could see every familiar note light something in him that he hadn’t allowed himself for what was clearly far too long.

He was easing into a song now, and your jaw dropped - you recognized the notes, imprinted on your soul in a way that not many musical arrangements could match. At your clear recognition his mouth twitched, a grin around his playing, tossing another wink to you.

“Fucking  _ Bohemian Rhapsody? _ ”

A single laugh rang out around his mouthpiece at your statement, but he drew himself back into the music, and you found yourself humming under your breath with a disbelieving grin on your face, the words memorized since you were little - because how could they  _ not _ be. You were completely caught by his performance, the music and his attitude lighting your own soul, making you forget for a strange and beautiful moment the circumstances you had found yourself in, the world shifting to simply you and him, sitting in his nest of blankets and pillows, a connection forged between you two in the most unlikely of ways but the most  _ right _ of matches. 

From there he slid into one that made your eyes light out and a laugh of disbelief pull from your chest as you cheered along when he hit the chorus. “ _ Carry on my wayward son-!” _

He kept playing, his tail swaying slighly to the beat, and you often falling into tapping out the beat with your hands on your thighs, sometimes singing along, sometimes just listening - there was an ease and rightness in the way he played the instrument that entranced you, slipping from popular older songs into jazz classics that could rival a musician heading a show in old New Orleans, with a comical but charming and confident attitude weaved into every note as he swayed immeasurably into the notes, drawing you into the experience with him.

When finally he pulled away the mouthpiece, you openly cheered, clapping and laughing as he fell into laughter himself, the sound rumbling and deep and so damn perfect you pushed towards him and lightly shoved at his chest, falling into further laughter with him as you both fell lopsided on the uneven seating. 

“You’ve been holding out on me, you damn jazzy skeleman! Where the hell did you pull that from!”

He snickered, the hand holding his instrument flopping away from you as he lazily swept the other one under his head, looking at you with one eyesocket closed.

*** pretty sure ya saw me pull it from under my pillows,** he said, his grin absolutely shit-eating.

“Okay, that’s it.”

Within moments you had snagged one of his pillows and before he could realize your move you had smacked him in the face with it, grinning as you lifted it and caught the surprised mock-affront on his expression.

The next moment his hand slipped from under his head, a blue glow about it - and then you were falling to the side, a pillow ringed in his magic whizzing into the side of your head. There was a wicked tilt to his returned grin - you mirrored it as you rolled to the side and grabbed a larger pillow to swing at him, laughing as he caught it and smacked you from behind with another, the trombone forgotten as it turned into a hilariously imbalanced pillow war.

The break lasted the rest of the day, long after a truce in pillow fighting had been called, not an hour passing where one of you didn’t have the other one bending over with laughter.

 

* * *

 

**June 26, 201X**

“If we turn it on, it might, you know,  _ work _ .”

*** that’s a big part of the concern, sweetheart.**

“Isn’t the whole point for it to work??”

*** yeah, but it’s more the ‘works** **_too_ ** **well’ i’m concerned about…**

“Okay, so… best case scenario, complete success, tidy door made, reach in, siblings found, celebration. Middle-ground scenario,  _ something _ happens, we at least, what, access it for a moment or two? Take notes, continue, push onwards, have a crapton more data to work with. Worst case scenario, well-”

*** -we tear reality in two and the universe collapses.**

“... Yeah, that does put a bit of a damper on things.

*** … but, on the other hand, we** **_probably_ ** **calculated things right-**

“I’m feeling suddenly distinctly less comfortable with the word ‘probably.’”

*** and i mean, we** **_are_ ** **at a point where damn near the only way forward is experimentation…**

“Okay, but… tearing reality in two??”

*** well that** **_is_ ** **the point, just - y’know, in a controlled way-**

“I’m feeling more and more like the walls of this cabin aren’t strong enough for the machine we’ve been working on for nearly a year.”

*** if it makes you feel better, walls don’t really stop a reality-warping extinction event.**

“You know, it really doesn’t.”

*** yeah, that’s fair.**

“...”

*** …**

“... We’re gonna do it, aren’t we?”

*** you know it.**

Your head fell into your hands, loosely shaking your head. You and Sans had been going back and forth for a while on this now, but it was true - it was time. You had tested everything shy of a true run that you could, the monster-sized chamber had been reinforced as many times as possible, the machine secured firmly to the ground - through the floor of the cabin, in fact, and well into the literal ground below. Numbers had been checked so many times over it wasn’t even worth counting anymore -

It was time.

Sans had turned to the large worktable along the wall, carefully tying a sizable leatherbound journal with the corded necklace you had made.

Naturally, you had both agreed you had to test with something other than either of you, first - stars knew that not enough testing had  _ already  _ smeared two people across time and space; you did not need any further risks on that front. But on the offchance that it  _ did _ work, you both wanted to send something meaningful through, something that if they found it, they’d know who it was from, and get something helpful out of it.

In the end, Sans had selected one of the handmade journals he took notes in - sized up to account for  _ his _ size - and specifically was a copy of the notes his brother had been taking, up until the point that he had been lost to the Void. The copy included all manner of expansions in notes, theories, and specifically many of the details of the work you had been helping Sans do for the past eleven-odd months. There also was apparently a vast array of additional loose notes in there of a decidedly  _ less _ helpful but more personal variety - that is to say, an incredible number of terrible jokes, crude but hilarious observations, and more. He tightly bound this journal with its strap, and around that wrapped  _ your  _ addition, meant for your sister. The notes for Sans’ brother would be more than enough on the helpful front, but you wanted desperately something for her too, something to tell her you were still there, still working and not giving up on her - something for her to keep. So beyond having a letter for her tucked within the journal’s pages, you had found sturdy leather cording and recreated a necklace for you that the both of you had loved back on the Surface. Its pendant included a small claw - something you found while rooting around in Waterfall some weeks ago - and a crystal stone, both hanging as the pendant from the length of cord. The crystal was one from Waterfall, gently glowing - Sans had helped you harvest it, given the crystal’s sturdiness. 

The two items bound together securely, Sans looked to you again, and you nodded. At that he turned to the machine, opening up the chamber and setting the bound items on the floor of it before closing it and securing it safely sealed.

He stepped back - this time, he had made sure to install  _ two _ panels, one on the machine itself, and an identical one situated twenty feet away, as far as you could stretch wiring it.

It too, was secured into the actual, literal ground.

He looked down to you as he came up to your side by the paneling, his gaze serious. Your heart was beating faster, anticipation and something more fueling the twin racing of your heart and soul alike as you returned his gaze. 

*** i’m gonna need you to do somethin’ else too, sweetheart,** he said, his low voice surprisingly quiet, though his words settled as firmly in your soul as they always did.

“What’s that?” You questioned. Your mind carded through a number of potential things that might need to be done before starting the test, but - well, you had already gone through everything, every possible preparation…

He was quiet for a moment, regarding you with an unreadable expression. His height and closeness forced you to tilt your head far back.

*** … hold onto me, and don’t let go until i say it’s okay,** he said.

Your eyes widened, a flush hitting your cheeks despite yourself. Before the silence could settle too long as your heart leapt into your throat, and before you could figure out what to say or think, he spoke again, his head turning away, his eyelights focused on the machine, a slight twitch to his expression for the shortest second.

*** … just in case. remember last time, with the pull? i know we reinforced everything, but…** he trailed off, his voice serious.  *** … i don’t wanna risk it. i** **_won’t_ ** **risk it. not you.**

His arm swept to the side, his gaze still towards the machine, still serious, but after a beat his tail twitched, and there was the slightest sheen of blue magic at his cheekbones. He waited, though somehow you could tell he wanted to screw waiting and simply scoop you against him - but he held off.

For you.

… You already knew how you felt about this, didn’t you…?

Your gaze on his chest then, you stepped forward, your arms circling around him, hesitant for a moment, and then gripping tight as his arm closed tight and protective around you, his tail sweeping over the floor to curve around where the two of you stood. You let your face remained buried against his chest for a few long moments, failing abysmally at slowing your heart rate as you caved in to the growing desire you had been having for… well… months, at least, to embrace him just like this. He smelled of pine and fresh snow, of the strange subtle yet wild scent of the echoflowers, and of something… warm, though you couldn’t quite put your finger on what it was.

After all this time, the scent that now wrapped around you… it felt  _ safe _ .

When your head finally turned, you looked towards the machine, not daring to try to look up to him - if you even could meet his eye. Your head barely rose above the bottom of his ribcage, even with him not standing fully straight, his posture slightly crouched in an almost primal need to be ready to move. 

He anchored you, and even though you missed the way his eyelights had dilated as your arms circled him, the rumble of his voice, just a slight bit delayed, warmed you as you felt it roll through his chest.

*** even if the machine interrupts my magic somehow, i’ll be able to hold onto you,** he said, looking forwards still.  *** so just hold tight.**

“... Got it,” you managed to say, a veritable storm of emotions and anticipation within you, though you clung to your focus on the machine with a fierce grip.

*** … ready?** He asked, his skull finally tilting down, gaze training on you to search for any hesitation or concern. He found none as you nodded, firm, meeting his gaze. A moment passed and he nodded back, his free hand moving to the panel in front of the two of you.  *** then let’s get this show on the road.**

In a deft chain of entered commands and failsafe codes, he started the machine’s full processing up and quickly slammed the final key, his clawed grip then going to the panel to anchor you both further as the machine’s soft, ever-present hum picked up and the machine began coming to life.

You gripped tightly at him, his arm circling you in turn more firmly, as you watched various lights come on in succession, and the ambient magic in the room began to charge, feeling like static against your skin as it responded to the incredible power behind the machine. The large panelling showing the filled gauges, pressure, and more began responding as sparks formed in the center of the chamber - before suddenly inverting, both in color - from white to black - and in  _ motion _ . You watched in fascinated horror as  _ something _ began to pulsate in the chamber, beyond sight but caught at the periphery of your vision, twisting like furious heat waves while the gauge dials in the panelling lifted higher, higher, venturing dangerously closer to the red zone as the gravity in the room began to shift, Sans’ grip on you growing tighter as your feet slowly left the ground, being drawn towards the machine as a sound beyond hearing yet head-splitting at the same time began to crash through the room-

There was a sudden and blinding flash of light that turned pure black as something exploded from nothingness to fill the chamber, everything deafening in the sudden dead silence as the gauges drained to zero and the light and blackness retreated in an instant-

-leaving only a small circle floating in the chamber, no bigger than a golf ball, and utterly pitch black. 

The journal bound in the necklace you had made was gone.

Your feet had hit the floor, but you hadn’t pulled back from your fierce embrace of the monster still protectively holding you flush against him. The machine had faded back to it’s usual hum, though it was just the slightest bit quieter now.

The circle of vantablack remained floating, unaffected by gravity, and utterly un responsive in reflecting any form of light.

“... Sans…?” You finally ventured, your throat feeling raw, as if you had been screaming for hours. You had a slight headache, but your focus couldn’t tear from the machine, your soul and heartbeat feeling suspended like the moment before an impact or a dodge.

*** … yeah?**

“Did we… just... “

*** … rip a hole in space-time and quite probably launch that stuff into the void?** he finished, his voice rougher than usual, as if he was suffering from the same raw effect as you. 

He hadn’t released you, either. 

*** … yeah, i think we did.**

“... Holy shit.”

*** holy fucking shit.**

**Notes for the Chapter:**

> did i say four chapters? i meant five. definitely five. and not because i kept adding scenes or anything because i have no self-control or anything, nope.


	5. Like a Bell

**Summary for the Chapter:**

> This next experiment looks like it's going to be very, very interesting.

**July 20, 201X**

Your footsteps were quiet, falling as silent as the towering monster you trailed behind. Sans’ ability to be utter silent when he wanted to never failed to amaze you - despite his size, he was incredibly graceful and light-footed. It had made you realize one day that he must make a conscious choice to make that slight amount of noise he usually did when he moved about the cabin, whether it was his tail brushing the ground or the slight shuffle of his claws against the floor - quite probably done for your sake. Given how many times you had nearly screamed in the early months of your time here when he seemed to suddenly appear behind you, well…

The thought made you smile.

All around you were fields of echoflowers, quietly murmuring in that way of theirs as you passed them, the slightest tap from Sans’ tail reactivating the messages in their blooms.

_ ‘Didn’t you hear? The barrier’s open!’ _

‘ _ That odd striped monster was really a human, I hear-’ _

_ ‘Do you think clouds are really as soft as they look?’ _

_ ‘Wait up, sis! We’ve gotta take a picture when we get there, okay?’ _

Your smile was warm, even though the words twisted emotion deep within your gut as they always did.

The first time you had passed through here with Sans, while the place was beautiful, you had felt like it seemed haunted. He had told you not to speak before going through, though - that your voice would overwrite them, yes, but to not do it. At the time, you had thought it weird of him, and chalked it up to what you figured was an extreme distaste for you - given it had still only been a couple weeks since your initial arrival.

Now though, you couldn’t be more grateful for how strongly he had spoken on the matter.

Waterfall was, frankly, your favorite part of the Underground you could actually visit. You liked Snowdin too, but  _ most  _ of your time was spent there, for obvious reasons. Meanwhile Hotland was a nightmare of heat, even though apparently it was actually far more vast than you had ever seen - the climate was too extreme for you to venture to in the rest of it, and Sans explained that while the architecture deeper in was cool, he’d rather just answer your questions on it if you had anything than watch your hair catch on fire less than a minute in. New Home was fascinating too, but… It’s emptiness was abject and desperately  _ lonely. _ It was emptied of course, but eerie remnants of the bustling signs of life it once showed were everywhere, only more starkly highlighting just how abandoned the place was. The Ruins were similar, albeit more dangerous and… older.

Waterfall, though… Waterfall was simply beautiful.

And outside of the tapes Sans salvaged for your stereo, the echoflowers native to its cavers were the only way you heard voices that didn’t belong to you or Sans.

Even if the snippets of conversation always stayed the same, largely providing  an odd snapshot in time from the mass exodus of all but one member of monsterkind still existing in this dimension, it was oddly reassuring - a strange tether to the fact that even if time passed and you remained alone, there  _ was _ life outside of here... something to strive for, proving this all as more than a dream or a break in your sanity.

Sans looked back at you as you reached the edge of the echoflower field, and you smiled softly at him. You could all but see the small huff of air exhaled through his nasal cavity, the flicker of a grin in reply across his maw something familiar and right.

You followed him into the next cavern, the echoflowers left behind in favor of the larger veins of glowing crystals that spiraled up towards the ceiling, the beginnings of what would eventually lead to the Wishing Room.

*** hard to believe, isn’t it?**

Your gaze turned from the crystals and the beginnings of their reflections in pooling water up to him, a question in your eyes. He looked at you for a long moment, reading something he saw in your expression, you could only figure, before he continued.

*** … do you know what day it is, sweetheart?**

Your brow furrowed. It had been a long time since you had bothered to look at the calendar you had originally kept after falling down here - time hadn’t had much meaning in that sort of sense, so it had been several months since you had truly kept track, but-

“... Wait,” you said slowly, counting the days in your head, remembering what month it must be, what  _ day _ -

*** it’s been a year since you fell down here,** Sans said simply, watching the realization dawn on your face.

You felt… shocked.

Before your mouth caught up to your mind to venture any sort of reply to that, you slowly began walking, Sans falling into step beside you.

“What the hell,” you eventually murmured. He huffed a short laugh at this, and at your generally dry tone of bewilderment. 

You had been trapped Underground for a year. Your sister, one year ago today, had been torn across space-time, sent to some eldritch dimension of nothingness and time incarnate wrapped into one, possibly with only Sans’ own brother to keep her company. The world above had forgotten her existence, and their minds would at best slide over yours, assuming your death with barely a passing thought before magic forced their minds onwards, unable to linger on what had happened to you. Hell, the only person in this reality that knew you were alive and actively thought about you, actively cared - he was walking by your side, towering over you in a way you had come to find comforting and familiar.

Here you were, one year later, strolling amicably with the monster you had assumed the worst of and brandished the nearest convenient branch at. Here you were, genuinely, deeply caring about him, considering him one of your best friends even by the standards you had on the Surface while  _ not _ stranded. Someone you had fought with, sure, but had bonded with too, working out issues in communication with him through mutual effort over time, slowly tearing down one another’s walls - even though some remained, it was of the comfortable and trusting variety… kept for your own personal reasons, not for lack of trust in one another.

Even then, you had shared things with one another that no one else would - or could - come close to understanding.

Water dripped more steadily now from overhead, making you shake your head slightly as it fell into your hair. Sans remained quiet, not pressuring you to talk, simply letting you think - but always by your side as you moved onwards through the tunnelled caves.

… You couldn’t help the stain of color on your cheeks as your thoughts kept going back to him.

If the circumstances were different, you might have honestly…

You shook your head again, more strongly, trying to cut that thought off - as you had been more and more frequently. You frankly had a lot of practice, now-

It was proving to be a daily exercise, at this point. 

Every time you looked up at him and he had that crooked grin over his maw, or when he was deep in focus in his research, or working with his claws deftly on the machine, or pulling out his trombone as had become ritual during at least one of his small breaks during the day-

*** … okay, do i have somethin’ on my face? at least tell me that much.**

You startled, your face flushing as you realized you had been staring up at him.

“N-no, sorry - just got lost in thought,” you managed to say, looking away quickly, flashing him a not-quite-convincing grin. You passed the umbrella stand then, only two lonely ones left. You grabbed the bigger of them, the only one without holes, and opened it up, and he took it from you as he usually did.

You didn’t have much of a chance of lifting it high enough to cover both of you, after all.

*** g for your thoughts, then?**

Your gaze stayed away from him as you rubbed one hand at the back of your neck, vaguely hoping that the dimmer light of this section of the caves would keep him from noticing the dark flush on your cheeks.

“... Just thinking about it all. About my sister, and what it’s like in there,” you said, hedging a bit, but not exactly lying. Your hand fell back to your pockets, your eyes only vaguely watching the steady, never ending ‘rain’ from the roof of the cave. “Whether she’s conscious in there, you know? If it’s like being asleep, or if she’s wandering, lost, if she and your brother have maybe found one another…” you trail off. Part of you really hoped that was the case. You could see - and guess - the toll that being alone for so long had taken on Sans… and while it was just the two of you down here which could be pretty taxingly lonely in other ways at times, you still at least had one another... and well, you were friends now, and if you were honest with yourself, had been for a pretty long time, no matter how you both had stumbled in your own ways. 

You sighed, your thoughts still lingering now firmly on your sister. “I know we’re doing our best, but I just feel...  _ guilty _ , too. Not only for her getting sucked in there, but… I guess for having even  _ this _ much freedom-” you gestured vaguely to the cave around you, to the soft mossy covering of nearby banks of dark crystalline water, to glowing stones and mushrooms painting a scene that could steal your breath away. “While she’s just… stuck in there, in some damned dimension of nothingness where time does and doesn’t pass, and gods know if she even found your brother and vice versa, or if they got along, or-  _ fuck _ , sometimes, sometimes I just wish it was me in there, you know? Not only so she didn’t have to deal with it, but- but so maybe, just maybe my thoughts could- could  _ not _ , you know-”

*** those thoughts’ll eat you alive if you let ‘em sit.**

You cut off a choked sob you hadn’t even realized had been rising as suddenly you found yourself being scooped against Sans’ chest, his free arm around you, unyielding and protective. 

Your hands went to ball in the material of the hoodie you had made him, tears pooling in your eyes as you buried your face against his chest.

“I can’t help it,” you managed to say, your voice cutting off unevenly. 

His arm tightened around you and you felt his body shift slightly, lowering into a crouch so your face buried against his collarbone instead. Despite yourself your arms looped around his neck, embracing him tightly as your body shuddered, a silent sob wracking through you.

*** i know,** he murmured.

His skull dipped down, and you could feel the side of it rest against your head. His steady breathing slowly shifted his ribcage, and you cried silently into his hold, safe and so terribly tired and grateful in one.

The minutes passed in a way you had long since ceased to count as he held you like that, the water pattering against the umbrella he held over you both. At some point his hand shifted, and his claws tentatively began to card through your hair, gently massaging your skull. The tears were still falling from your eyes but you slowly quieted, the soothing motion welcomed down to your soul.

“... I’m glad I met you.”

The admission was quiet, a whisper into the slightly damp fabric of his hoodie, nearly lost among the patter of the water against the umbrella. 

His hand stopped against the curve of your scalp, resting there.

He didn’t say anything.

Somehow, you didn’t need him to.

“Sure, the circumstances are shit, but…” You hugged him tighter, falling into this moment of true vulnerability-

-not wanting to let go.

“You - you… mean a lot to me, Sans. Thank you.”

Your face was hot, under your tears, and you hid it against his shoulder as you felt his ribs seize slightly - a physical sign of his breath catching. 

Recently you had been looking through some of the notes from your earlier development of the machine - back in the first few months you had arrived down here, when you were still deep in your desperate attempts to get up to a decent speed with the concepts and applications of magical theoretical physics amongst the rest. You wanted to double check some of the choices made in the earlier development, to cross reference with a more recent decision made after the test that had sent the journal and necklace into the Void and created a tiny, unbreakable hole in reality still contained in the machine…

The notes had confused you at first, which had surprised you slightly. They seemed to indicate that Sans had been doubling back and redoing things, mentioning a few actions and key figures in a shorthand you didn’t recognize from his usual notes -

It was then that you realized that he  _ had _ been doubling back. 

The entire time he had been teaching you, he had been a firm but steady teacher, not seeming to allow much error, but coaching you and pointing out the flaws in your work in a solid and understandable manner before expecting you to tackle it again. As you transitioned towards helping him with the machine, the process had continued, and you figured he had just slightly adjusted minor mistakes and continued onwards given how exacting he was when it came to this - but through his notes, you found out that he had been letting you do work, learn practically and by hand - the way you always did best - and whenever you went to study more or do research, he took apart what you had done, studied it to catch any points you needed to improve, then rebuilt it himself to ensure that everything would work, and you wouldn’t later notice a part you worked on mess up and feel the painful consequences of guilt for it. He never lightened his expectations, or pretended your work was far more excelled than it was, ensuring you’d actually grow - but his backend work had gone so much further than you’d ever suspected.

He was like that in so many ways, you had come to realize.

Sans showed he cared in his actions more than anything, but he’d never explain or even mention what he’d done half the time - making much of it easy to miss. From how he had taught you, to how he had apparently constructed the water heater for your showers himself - apparently improving the design over time to prevent the supply from cutting out as much… to how he built that stereo that was now well-loved and well-used by the both of you - to how he even had started to pick out the books that you salvaged in your runs to the Waterfull Dump, and would return with similar ones when he made individual runs, casually placing it with the other few ‘communal’ things he’d picked up.

Ruminating on it all made you laugh, wetly, into his embrace. He jolted slightly at that, but you shook your head into his shoulder and dragged yourself closer to him. Your feelings were raw in your chest, but somehow, pressed against him - it all felt bearable, and he kept dragging the warmer ones to the forefront, just by… being there.

Suddenly you half-squeaked as you felt yourself lifted into the air. Both of Sans’ arms were around you, the umbrella left to hang haphazardly off his horns, mostly covering you still. His skull buried downwards, tucking you under his chin as he held you secure. Your full blush was hidden, to your gratitude, but you were left completely breathless.

*** … d’you like stealin’ my lines, or what, sweetheart?** he murmured, his voice somewhere between a grumble and a poorly hidden purr his instincts wouldn’t hide.  *** … fuck. y’know you… well, you’re the best thing to happen to me down here.**

The rain slid off the lopsided curve of the umbrella, wetting the outer curve of his arms, though you stayed dry.

By the tiniest fraction his embrace tightened.  *** uh. not that i want you to be trapped here too- i just mean - and beyond the general feelin’ of ‘dear fuckin’ hell i’m gonna go insane if i don’t have someone to talk to’ - you’re actually -** He tucked you closer to him, as if he didn’t want you to see his face.  *** … havin’** **_you_ ** **, specifically, around is… everythin’.**

You couldn’t help but wonder if that blue magic of his was spread over his skull. Part of you wanted to try to pull back, tilt your head to see it - gods, you always got excited when you managed to get him to laugh or otherwise react enough to get it out of him… but well, then he’d see  _ you  _ blushing.

“... We’re a couple of dorks, aren’t we?” 

*** takes one to know one, or something, i hear.**

You laughed, taking advantage of the continued, purposeful nearness to memorize how oddly safe  you felt, how absurdly  _ strong _ yet controlled he was…

“Guilty as charged. Take me away,  _ Serif _ Sans, this cave’s too big for  _ two _ dorks.”

He snickered at that. A little reluctantly, he slowly set you down, looking up and towards the ceiling as he took hold of the umbrella again.  *** yeah, can’t be seen hanging around with a** **_human_ ** **dork. think about about what the cave walls will say.**

Snorting, and acting on an instinct you finally chose to not shove down, your hand grabbed his and you tugged him forward and onwards into the cave, glancing back at him in a way that for the briefest moment, betrayed your grin and your bright, clear blush as you wagged a brow at him. “Hey, maybe that’s what echoes are - the walls can’t keep a secret so they just yell out what we tell them the moment it reaches them.”

Sans’ eyelights had dilated, and you found your own betrayed blush rewarded with the sight of a cerulean glow over the crests of his cheekbones as his eyelights lifted from your joined hands to your face. He recovered his expression quickly, his brow lifting before he feigned distress.

*** an usurper to my science throne, tossin’ such** **_rock-solid_ ** **theories out, erodin’ my position in these hallowed caverns-** he broke slightly, grinning in that lopsided way that showed enough fang to theoretically be unsettling - but to you was so  _ him _ that it just made your own grin grow.  *** i better keep an eyesocket out, lest she** **_tail_ ** **me ‘n take my hard work.**

He tapped you in the calf with a sweep of his tail, and your laughter only made his own chuckles deepen and his eyelights brighten as you made your way to the Wishing Room together, hand-in-hand.

 

* * *

 

**August 4, 201X**

“... I think we should name it.”

*** that is the** **_worst_ ** **idea. and yes, i’m takin’ into consideration when i suggested seein’ if bubbles would collapse or expand ‘n explode if we managed to blow ‘em in there.**

“Damn, I think you might have mispronounced ‘ _ best _ idea.’”

*** what the** **_hell_ ** **do you name a black hole, anyways?**

“Well it’s not  _ technically _ a black hole, as you kept saying…”

*** yeah but now i’m pretty solidly on standin’ by your earlier statements that “reality-warping 4th dimensional spheric hole that may or may not be tied to the void” is a bit of a mouthful.**

“Just a bit.”

Sans rolled his eyelights shaking his head with a grin as he jot down some more notes.  *** alright, alright, fine. a name. you got one, or…?**

You turned towards the machine and sighed heavily, as if bearing the heaviest burden. “What names  _ don’t _ I have.”

*** that feels like a trick question.**

You shot fingerguns lazily at him, turning back around - just in time to catch him rolling his shoulders for the umpteenth time today.

When he looked back up from his notes, you were standing in front of him, hands planted on your hips and a determined sort of glint in your eyes.

“Scoot forward, boneboy.”

*** … but i’m comfortable?**

His bone brow lifted at you, not sure what game you were playing - but despite himself, his grin grew in that crooked way you liked so much. 

You grinned back at him. “C’mon, don’t you trust me?”

*** of course,** he responded instantly. After a beat his tail twitched, his eyelights moving away.  *** c’mon, sweetheart, that’s gotta be cheating-**

Ignoring the way your heart had skipped a beat, you shook your head. “Just scoot forward, Sans. You can still be on the pillows, don’t worry.”

With a bit of grumbling that had no heart in it, he lazily and deliberately slowly inched forward in his nest. You just rolled your eyes at him while he made a show of it, but once he was more or less done you clambered in and shifted some behind him until you were seated with your legs tucked under his arms,  with your hands resting comfortably on his shoulders.

… Ever since the few weeks prior where you and Sans had that moment under the umbrella, eventually clasping hands for the rest of your walk through Waterfall, not  _ too _ much had changed… though you noticed that particular blue dusting over his skull more often, and your own blush was coming more frequently, too - but still you had more… casual physical interactions than you had previously. His hand settling on your shoulder as he read something you held up for him, you leaning against his side as he pointed out an adjustment to be made on the machine, his tail tapping you to tease you, your hand occasionally brushing over his hand… You had even passed out side by side a few times in the past week, after hours of reviewing notes and hashing through theories, occasionally getting distracted by commentary and stories stemming from noticing a line in a song that played in the background.

Still, though, this was much more deliberately close than all that. You felt him tense, too, though not in the way you knew meant he was uncomfortable - more in the…  _ anticipation _ sort of way.

“... I’m told I have a knack for massage,” you managed to say, your smile picking up again. At least he couldn’t see your face like this. “No promises, what with the living bone and all, but maybe it’ll help at least a little.”

Your waited for a moment, seeing if he’d shrug you off - but after a few seconds, he settled back just an inch, his skull tilting to look at you.

***** **_tibia_ ** **honest, sweetheart, i’m a little concerned you’re gonna end up in worse shape than i am, but i** **_also_ ** **get the feelin’ you’re not willin’ to let this go.**

His voice was wry, but a grin was on his face, that same lopsided one that made your heart beat faster. You grinned back, nodding. “Definitely not letting it go, big guy. For not having any muscles, you sure do get tense.”

*** well, with such a** **_sore_ ** **topic…**

You laughed and smacked him in one of his arching horns, making him snicker.

“I  _ will _ tickle you,” you threatened.

*** i have a tail, and i’m not afraid to use it.**

“Duly noted,” you replied. Before he could open his maw to continue, your grip shifted, a sly smile on your face as your thumbs shifted over his shoulders, working against his bones.

It was something you had noted before - that despite his appearance, his bones had the barest amount of give to them. You weren’t sure if it was selective, but surely it had to do with the fact that he was truly a monster, not just a skeleton of some part-dragon-esque creature come to life. It made it easier than you had worried it would be, since that fact made it feel like you were actually doing something as your fingers smoothed over the surface of his hoodie, slowly working from his vertebrae, down his shoulders, over his shoulderblades…

Sans made a choked noise suddenly as your hands worked with steady pressure back to his spine, trailing over his spinous processes. You froze for a moment, about to ask him if he was okay- 

And then he started purring.

Your brows lifted as his posture eased further and he tilted his skull, his form pressing willingly back towards you.

*** i know i’m supposed to be the magic skeleton, but h-** **_hell_ ** **-** his voice went rough for a moment as you tentatively continued, your thumbs now working firm but gentle along either side of his vertebrae.  ***** **_you’re_ ** **the one with the magic touch here, clearly-**

Your face flushed as you grinned at the back of his skull. Apparently you had flipped a switch in him, turning him into a willing, purring pile of docile and pleased bones pressing back into you. It must have been those more primal instincts of his, but you couldn’t help but be a flustered sort of pleased that it was you taking the chance to try to ease some of his clear aches that had made him relax like this - in a way you hadn’t seen before, even after over a year of living together. 

“Pleased to be of service,” you replied, your mirth clear in your tone. 

The end of his tail was curling, swaying in an expression of his unexpected contentment, the length of it curling to half-scoop around where you sat perched behind him. 

*** hold this over me for the next century, i don’t care. just - oh stars, don’t stop,** he groaned, one of his legs twitching before it stretched out as he curved his back for you to access certain spots easier. 

… Frankly, you didn’t mind fulfilling that particular request.  _ Certainly  _ not when he asked like that.

His frame had always not only  _ looked  _ powerful, but  _ felt _ powerful to you, and to feel it shift under your touch like this was mesmerizing. You had seen him barechested a few times before - namely when he took off the hoodie you had made him when you were deep within the Waterfall dump and he had to get into the waterfalls themselves to heft out larger items you needed to move. Most of his joints interlocked, plating together with sometimes the faintest glimmer of magic catching in the light along the plated lines. His bones were broad and sturdy, infinitely thicker than an actual skeleton’s would be, even one that was sized for his height. There was  _ power _ behind them, even beyond the apparently absurdly strong magic he could wield -

\- and here he was, pressing back into your touch like an enormous and utterly pleased cat. 

“I’ve never seen this side of you,” you murmured. The words left you before you could stop them, your own soul having eased for his relaxation. 

*** mmmm.** He seemed to be having trouble forming words, but his head tilted to the side to grant you better access as you worked your way back up to his shoulders.  *** … hadn’t had much of a way to let go this much.** His purring barely ceased as he spoke, so low in his chest that it all but vibrated against your legs.  *** … ‘s’a bit embarassin’.**

He grumbled that last bit, but your massage was clearly working wonders on him. You weren’t sure if it was the fact that both of you were probably a little touch-starved even though you had been more casually physical with one another recently, or if you really were hitting the right spots by chasing instinct and his reactions, but either way he was still relaxed in your hands, reclining further.

You felt like this was an enormous sign of trust from him. The realization settled warm and bright within you, making you bite your lip lightly.

“... I like it,” you said quietly, your voice more than a little warm. “It’s cute.”

His tail twitched at that, accidentally brushing your side before shifting away. 

*** that doesn’t make any sense.**

He half-mumbled that bit, but still seemed unwilling to shift away.

You shrugged lightly, once again glad he couldn’t see your face. “...  _ You’re  _ cute. Large and spooky scary, sure, but you’re just a big old soft nerd on the inside,” you teased, your face warming, but a grin on your lips regardless.

Sans sputtered slightly at that, seeming for once at a loss for words.

*** that’s cheating,** he managed to say finally.  *** you can’t just - just say shit like that when you’ve got my - when you’re touchin’ me like-**

Your hand shifted, your thumbs dragging on either side of his spinous process near the nape of his neck and his words choked off before rolling into a groan of a purr as his skull fell into a large pillow he had grabbed.

*** y’r th’ wors’,** he mumbled into the soft surface, making you grin as his tail lightly bat at you while you leaned in to continuing to work the spot. 

“Yeah, I like you too,” you shot back with a snicker.

Your fingers stuttered in their motion as you mentally tripped over the slip, desperately hoping he took it absolutely in the platonic way and not in the  _ more _ way your voice had leaned into-

“So, Sans, if your brother was a scientist like you, what about your little brother? He doesn’t seem to make it into your tales from working in the lab,” you said a little too quickly. 

It seemed to offer him an out you weren’t sure why he so gratefully took - maybe he was still embarrassed about the cute thing? You didn’t question it, instead thankful for the quick switch in topic.

*** oh, uh - yeah, no - he was always more into puzzles ‘n acts of cool adventure than science,** Sans said, his own voice a little quicker too despite the way he relaxed back into you once more as your hands picked up their work again.  *** he was more’n smart enough, but it just didn’t capture him the same way it did the two of us. by the time he was a teen he wanted to be in the Royal Guard, though he always was too good-hearted for what they were expected to do when a human came around,** he said. His skull was turned just slightly towards you, his head resting on the pillow in his arms - you could see that his sockets had fallen shut.

He didn’t talk much about his little brother, not even once you both had opened up so much more to one another over time. But then again, you didn’t talk much but in passing about your friends on the Surface, or your old life - for both of you, you suspected, it was still a little too hard, and a little too easy to fall into the trap of wistful regret and ill-gotten longing.

“He sounds like a friend of mine on the Surface,” you replied a little more softly, a sad smile on your face. Gods, you really did miss him, and the rest of the small group of tight-knit friends your sister and you had left behind when you’d fallen down here. It hurt to think that they probably thought you had died, if they *did* think about you - and that they wouldn’t remember your sister despite how close you all had been, no doubt…

Sans seemed to recognize your attempt to be similarly more open, too, in this moment. His head tilted towards you a little more.  *** … must be one hell of a friend,** he said, his low voice an odd sort of caress that you appreciated deeply.  *** yeah, in the end, he was a sentry - technically a potential pre-Royal Guard type of post, if you could prove yourself. i was one too, with him - mostly got up to a lotta japes deep in the forest, settin’ up puzzles with him, sellin’ ‘dogs,** he chuckled softly in memory.  *** heh, Pap always pretended to hate my quality puns too, but-**

Your hands stopped moving suddenly, and he cracked an eyesocket open curiously towards you, almost looking disappointed, or maybe concerned, but your eyes had gone wide as you gaped at him.

“Wait- Pap?” You breathed. “I don’t - you don’t mean  _ Papyrus _ , do you?”

Sans’ visible eyesocket opened wide then, his eyelight sharp on you.  *** do you know him?**

One of your hands lifted to your mouth, completely shocked, but a smile was picking up on your face as your eyes started to prick with heat. “Holy - do I know him? He’s - he’s one of my best friends,” you managed to say. Over a year later, and you could still picture him clearly in your mind, having been close for years by then- “He’s your  _ brother? _ **_”_ **

Sans’ jaw was hanging slightly open, staring at you as shocked as you were staring at him.  *** yeah, he- fuck-**

Suddenly his body had twisted and he pulled you into sprawled into his lap, his arms supporting you as his eyelights seemed to waver, magic sparking at them.

***** **_fuck_ ** **, sweetheart - he - is he okay? or- or was, he i mean, i know that- i just-** **_please-_ **

Your hands were grasping at his, flushed in surprise at your sudden new positioning but you were being slammed by the revelation almost as much as he was. “No, of course - he was fine, he was - he was doing well,” you said, your eyes tearing up at the same time his were. “He - he was working two jobs, one parttime with Frisk, as a sort of-” you couldn’t help but laugh wetly, flashes of memories of you boisterous and charming friend posing and sharing tales of his ‘knightly adventures’- “-mascot-bodyguard with Frisk whenever they made appearances in public, and the rest of the time he actually had been working in a flowershop that’s gained a lot of renown as not only having gorgeous flowers but also having a charming skeleton who can create any damn message you want with flower language,” you choked in a half-sob, your heart torn between joy and sorrow. 

Sans’ eyelights were searching your face, a similar war in his expression shared by awe.

*** th-thank the stars,** he whispered, almost brokenly, before the magic slipped down his face.  *** i-** **_fuck_ ** **, sweetheart, he’s really doing alright- hell, he made friends with someone as great as you, that’s** **_gotta_ ** **mean he’s doing well-**

His skull bowed downwards, close to you, his eyesockets screwing shut as his tail curled around you both and he pulled you closer, practically embracing you as the wave of emotion took him. Your own tears slipped over your cheeks forgotten as your forehead inclined to press against him, your hands clutching his in reassurance and support. 

“He really is,” you managed to say, utterly refusing to use the past tense despite the year that had passed. “He lives with our other friends, Undyne and Alphys, and we always hung out a lot at this coffeeshop owned by someone named Muffet, er, when she wasn’t temporarily banning or charging them for accidental property damage that is-”

Sans choked out another laugh at that.  *** you’re friends with th-them, too, of** **_course_ ** **you are-**

One of your hands lifted tentatively to his skull, hesitating for a moment - but then you caved to your instinct and wiped away his tears gently. “You- you know Undyne and Alph? or Muffet?”

He shook his head gently, making you doubt your understanding for a moment, but then he continued,  *** do i know ‘em - ‘course i do-** his voice was rough, but his maw had twisted into a smile, the kind laden with such fierce emotion that would be hard to understand if you hadn’t also been trapped Underground with your dearest friends having all but forgotten you, no matter how much you cared for them or wished to be back with them. 

*** i used to work with Alphys in the lab - ‘n Undyne was always around, bein’ captain of the Royal Guard ‘n all, ‘n Pap’s best friend,** he explained.  *** i wasn’t as close with Muffet, but we shot the shit a lot whenever i was around Hotland-**

Sans’ head lifted then, just enough to properly look at you, but he didn’t tilt his head away from your hand. There was a kind of wonder and awed disbelief in his expression. It was making you flush again, though you didn’t look away.

*** how’d you meet them…?**

“My - my sister and I actually met them at Muffet’s… We both are addicted to coffee, so when her place opened up just down the block from our apartment within a few months of monsters coming to the Surface, we both went to check it out, both because we were down for a coffeeplace close by and to make sure it wasn’t like some of the other monster businesses that were opening that had trouble thanks to some bigot humans boycotting them… aggressively,” you said, the memory playing easily through your mind, though it felt like your words were coming of their own accord as you got lost in the way Sans was looking at you. 

“We hung out for a long time that afternoon, actually, ending up talking with Muffet a lot, and then-” you couldn’t help but laugh under your breath for a moment, your gaze twisting fondly. “-and then Pap and Undyne burst in, announcing that the ‘party could officially start’ because the coolest monster had arrived - they then got in a wrestling match because they both insisted simultaneously that the other was too cool, and next thing we know suddenly the table next to us was being destroyed by a misguided suplex-” You shook your head, both your and Sans’ wet gazes sparking in clear mirth at the thought. “It was pretty hard to not end up striking a conversation after that, as my sis then jumped up to help Pap who had started shouting about being able to put the table back together like a puzzle easily despite sweating bullets while Undyne went and paid Muffet twenty times the price for a couple of cups of coffee neither of them probably needed. From there, well…”

*** once Pap decides you’re friends, that’s it,** Sans said, a hopeless and fond laugh catching in his chest. 

You echoed it, your eyes shutting for a moment as flashes of moments in your friendship passed through your memory. The first time you and your sister had ended up being dragged to hang out with them ‘properly’, the way Undyne’s kitchen had caught on fire on  _ more _ than one occasion, the anime and MTT nights, the video game contests, the drinks and the coffee, the commiseration, the protests that you and your sister had made sure they got safe through - 

You opened your eyes again to ask him what else he wanted to hear about Pap, or his friends, or if he just wanted to hear stories-

But the way he was looking at you made your heart skip a beat, and your hand still laying over his much broader one clutch slightly tighter at him.

*** … y’know, sometimes i wonder if you’re really the one the prophecy meant…**

Your breath caught in your chest. 

After all, you had walked those trails in Waterfall countless times now - hell, you probably had those plaques memorized…

_ The Angel... The One Who Has Seen The Surface... They will return. And the underground will go empty. _

You blushed at the implication, at him referring to you in such a way, however roundabout-

Still, your hand on his cheekbone drifted along the curve of his skull to his jaw, unable to look away, feeling entranced by his gaze. You opened your mouth, ready to say something, but - nothing came out.

His arms circled you, the comfort you felt in how sturdy and broad they were extending into something more, something that had been heating in your veins for months now - first as though you had merely passed close to a fire… now feeling as though you stood in the very depths of Hotland. 

His eyelights had dilated slightly, looking like their own stars in his sockets as the room seemed to fade away in the background, even as the music played on quietly, below conscious notice.

*** … how do you do it?**

His low voice merely pulled you closer rather than startling you.

“... Do what?” you said, a little breathless.

*** overturn my world every time you look at me.**

It felt like the air left the room.

The next moment you closed the last of the distance between you, heat sparking through your veins as your lips met his mouth in a movement so instinctive and natural it felt like the final crack had splintered the resistance of a dam. 

He was so much larger than you yet you’d never felt safer or more wanting or more  _ wanted _ . A sound like thunder rolled through his chest as he dragged you as close to him as he could manage while still kissing you. The malleable bone of his mouth moved against your lips, making you gasp and clutch at him, heat in your belly as your worlds finally collided fully.

His fangs carefully nipped at your lips and you gasped in response, opening your mouth to his which he took full advantage of, his sparking magical tongue meeting yours. Your passion in return to his made him groan against your lips, and you lost yourselves for an indeterminate amount of time as fire lit you both from deep in your cores, no hesitation paid for the difference in your sizes, or for how long you had been toeing around your fierce attraction to one another.

When you finally broke away from one another, panting and flushed, you stared into his eyelights with passion-hazed eyes, him looking just as wrecked as you.

“... Sans,” you managed to say at last, your hands now thoroughly tangled in their grip on his hoodie.

***** **_sweetheart_ ** **,** he responded in a voice so husky it shot desire straight to your gut with a shiver racing down your spine. 

“... Dear god, please don’t tell me that was a one time thing,” you managed to whisper, the faintest hint of a grin beneath your breathless expression.

He purred in response, his eyesockets lidding as a decidedly wicked grin appeared on his maw.

*** the name’s Sans as it always is,** **_angel_ ** **…** His eyelights flashed as he bowed closer to you.  *** but i’d be happy to answer your prayers.**

You gasped in laughter then as he rolled you over, settling your back into his nest of pillows and blankets and arching over you. His head nuzzled against you then, nearly taking you by surprise, and you could feel his purr.

*** … thank you, angel,** he murmured, his forehead butting up gently against yours.

One of your hands lifted to trace along his jaw, a blissful yet excited and flustered smile on your lips. “For what…?”

*** … for comin’ into my life ‘n turnin’ it all upside down. i wouldn’t wish this fate on anyone, but havin’ you here - ‘n not just anyone, but** **_you_ ** **…**

One of his hands traced down your side then, reverent.

*** you make my soul sing,** he said, his voice a whisper.  *** when i had damn near given up all hope, you busted in with that sun-like soul ‘a yours, and just… changed everythin’. changed** **_me_ ** **.**

Your hand still on his hoodie shifted to your sternum, feeling the way your soul seized in nothing short of flustered joy at his words, thanks to how aware as he had helped you become of it even within your chest. 

“Sans, I… fuck. Even if we had been only ever on the Surface, I need you to know-” your head pressed back with equal tenderness against his. “... I’d still want you,” you murmured. “Again, and again. Hell, you’d have to try hard as hell to shake me - that’s how right you feel.”

He chuckled then, something rich in the sound, the way you felt you heard his voice in your very soul starting to make a whole lot of sense. 

*** angel, you’ve got somethin’ else comin’ if you think that’s gonna happen.** His arm around you settled closer as he pressed down more towards you, his sockets lidding once more.  *** because you’ve spoiled me this past year. i’m addicted to it, now, ‘n i wouldn’t have it any other way. all i want is to see you by my side… or better yet, in my arms… that smart mouth of yours goin’ off on our work, your eyes sparkin’ up at me in that way you’ve got about you… the way you move next to me,** **_against_ ** **me - the way your passion shines through in any damn thing you do.**

He had stolen your breath again, but you didn’t even want to fight it -

Instead, your hand along his jaw slid further as you tilted your face once again, kissing him with every ounce of passion you had to express how you felt, feeling him return your kiss just as intensely, time slipping beyond notice as you fell fiercely and willingly into one another’s fervor.

 

* * *

 

**October 21, 201X**

The sides of Sans’ scarf draped around your shoulders like a cloak, warming you nearly as much as the odd magical heat his body exuded did as you relaxed back into him. Your legs were bent, your knees closer to your chest as you both looked over the lower levels of the Snowdin cavern, while Sans’ legs hung over the edge of the cliff, his femurs on either side of you. His hands rested around your middle, holding you close and keeping the chill of the cavern from getting to you.

“The fact that it’s still holding steady, what, three, nearly four months later… that’s good, at least, right?”

Sans’ chest rumbled slightly in response to your thought.

*** probably. but openin’ the chamber’s still a no go - ‘specially since we just confirmed it’s warpin’ the magic within’ the container…**

You sighed, nodding. Even if the golfball sized mini black hole - or tear in reality, or  _ whatever  _ it was - could connect to the Void… it was too big a risk to take to open up the chamber as things were. It could destabilize entirely, sucking both you and Sans in, or exploding in size, or destroying the machine - any number of things. You had long since made backup notes and put them in a few different safespaces around the Underground in the event of the machine and the cabin alike getting damaged, but rebuilding would still take a long time - and you had come so far…

“The fact we’ve made it this far  _ and _ kept it so stable makes me sure that there’s a way to do it, though,” you said more firmly, your hands tucked into his. You tilted your head back, looking up at his skull. “There’s something we’ve gotta be missing… but we’ve ruled out a lot so far, so we’ve got to be honing in on it, on  _ something _ to bridge this last big gap.”

It was something that you had to tell yourselves frequently, alternating in keeping one another focused. It had been about three months since you and Sans had first kissed… admittedly, you did have more frequent and decidedly enjoyable  _ distractions _ now - but you tried to minimize it to the positive ones as you took breaks together, trying to keep the marathon mindset and not burn out. 

*** i wish i could still access that damn teleporting magic,** he grumbled above you.  *** i always felt like it had something to do with the Void, but never could get proper measurements on it… and ever since i got stuck like this it hasn’t been an** **_option_ ** **.**

You hummed softly at that, and he turned his skull down towards you and canted his head slightly so one of his eyelights could catch your gaze.

You answered his silent query readily. “You never talk much about what happened, or what you were like beforehand,” you said slowly. You knew that he had looked different, apparently - causing the connection between him and Papyrus to make a lot more sense than a general ‘skeletal’ theme - and that he had been stuck down here when the barrier broke, unable to do anything as it was resealed somehow, but… that was it. You didn’t press on it, and he didn’t explain further. You figured he’d tell you if it was relevant or when he was ready, even if you were  _ extremely _ curious.

But, well… it sounded at least  _ slightly  _ relevant now.

“... Your  _ magic _ changed?” You said, a question and a prompt both, one he could take or leave.

He was quiet for a long time, though one of his thumbs slowly skated up and down your side.

*** … yeah. not all of it, though - i still had blue magic, gravity based and all, and bones and all that jazz…** He shrugged slightly.  *** the core of my magic was the same. the big differences though are that i used to be able to take shortcuts - basically teleport, so long as i had been to the place before - and i used to be able to summon blasters, that, well,** he rolled his visible eyelight, his expression wry. One of his hands lifted from you, and he tapped the side of his skull near his temple.  *** they looked like what my skull looks like now.**

Your eyes widened at that. “Wait, seriously?”

He chuckled dryly.  *** yeah, seriously. could call up multiple of ‘em and everything - they could charge a blast of magical energy like i can still do now, just, y’know, now it’s outta my mouth.**

“... Well, shit,”

*** pretty much.**

His hand lowered back down, propping himself back slightly in the snow, causing you to recline with him.

“... It’s alright if you don’t wanna talk about it, but… can I ask what happened?”

His hand on you shifted slightly, one of his claws idly playing with your own much smaller scarf. It largely matched his, given that you had made both of them - yours was just almost comically smaller, naturally. 

Finally, he sighed.

*** yeah, it’s not like… well, there’s not a point in keeping it secret, really. it just… isn’t somethin’ i like thinkin’ about.** You could almost hear the frown in his expression, and your hand shifted lay over his - his was nearly twice the size of yours. 

*** see, when the barrier broke… we were** **_all_ ** **in this kinda liminal space. as much as i can remember, Frisk had fought the fuckin’ flower asshole that tried to take all the human souls t’become a god… they got through to him, somehow, overcame it all because** **_of course_ ** **they did - ‘n next thing i know, i felt the barrier break - all of us did. the flower had half-absorbed us all, turnin’ us into lost souls on the brink of Fallin’ permanently - but Frisk had reached the core of him ‘n the monster he used to be - ‘n since all our souls added together provided the power equivalent to one human soul… they must’ve broken the barrier that way, without havin’ to take Frisk’s soul.**

You had known about the human souls even on the Surface - that had been a big point of contention, after all, though everyone was a little hazy on the ending of things, and the King and Queen had given a simplified explanation. This was more though than you ever had heard about the actual events, and part of you wondered if a reason why everyone’s memory slid over it so firmly was Sans’ involvement, and their memories  _ needing _ to slide over the last they saw of him to plant the vague story of him just not being around anymore.

*** thing is, there was somethin’...** **_bad_ ** **left behind. all the negative emotions ‘n intent built up in the human souls, ‘n i figure maybe us monsters too… it was pulled into one area in the big strange space all our energy was in, and the malicious** **_thing_ ** **that clung to Frisk, what was left of its intent, anyways - it clung to that power, small as it was.**

Your breath had caught in your chest, his story consuming your attention as you stared over the gentle snowfall in the distance.

*** it taunted me - clung to me, tried to cling to the others, too, but i tried to block it off. i always had a knack for perceivin’ it from the very beginning - the weird malicious ghost that shadowed in Frisk’s footsteps, that is - thanks to the fact that my power was deemed to be that of a Judge, meanin’ i can read souls. i was forced to stand as the judge, jury, ‘n goddamn executioner should a human make it that far. i hated the fuckin’ job, but i didn’t get given a choice.**

Your hand soothed along his knuckles, your soul aching sharply. You heard his tail before you felt it - it shifted, slowly moving to lay over your lap.

*** … the ghost… thing, it threatened to destroy it all. i was trapped in that space with it, barrin’ it from goin’ further, but it was takin’ a toll on me over time - ‘n finally, it said fine, it would give up, it would disappear - but** **_someone_ ** **had to pay for everyone’s sins. all of them - looped through time and time again thanks to the fact that Frisk’s determination could bend and reset their days in the Underground at will - ‘n all too frequently, when the ghost proved too strong ‘n temptin’ ‘n took the reigns, they’d massacre** **_everyone_ ** **.**

His voice dropped lower.

*** … and i mean everyone. my determination’s not high enough to remember them all, even though experiments i had done in the lab with my bro have mine far higher than any other monster’s.. but i have a sorta dream-like memory of all the timelines. or nightmare, to be more accurate. hundreds and hundreds of times, countless years… looped again, and again. i had long lost my mind, and woke up more often than not feelin’ like i could still feel Pap’s dust on my hands…**

You were both silent, but you shifted, kneeling then as you faced him, your arms going around his torso to embrace him wordlessly. His hand shifted, holding you closer as he supported lifting you off the ground to lay over his chest. The warmth of his soul in his chest, beyond physical reach, hit you in your very core, and you kept hugging him.

*** … anyways, they said that all those loops - even if they weren’t** **_this_ ** **time, they still happened - and as Judge, they said i knew that it had to be paid for, too. i could either trap Frisk down here instead, they offered, to spend an eternity paying for their sins and the sins of everyone else… or... i could take their place. said their intent combined with the lingering malice from the other souls was more than enough to trap either of us. even with Frisk’s determination, there’s not much that can stand up against that kinda pure hate - from something like that… that LV is too high. haven’t found a way to break either the barrier or whatever they did to me - i’m guessin’ they tried to seal some of my magic away, but it got twisted somehow. haven’t heard a whisper or hint of ‘em since… seems like it really was their last act ‘a spite, sealin’ the Underground like that again… when i woke up, i was alone on the wrong side of the barrier… everyone else gone.**

He fell silent then, his arm around you a gentle embrace, his thoughts seeming miles away. 

Finally, you murmured against his chest. “... You took Frisk’s place.”

He simply nodded.

Even after everything he had been through because of them...

“... Why…?”

He exhaled, the magic-warmed air clouding in the chill.

*** i ask myself that more often than i’d like to admit,** he responded. You waited quietly, still embracing him.  *** … honestly, though? i don’t… i don’t think it was all Frisk that had done that. not that i think they’re perfect or innocent, either - i know they made bad decisions too, and it was those that the ghost latched onto to steer them towards no mercy so many times, but…**

He sighed.

*** i can judge intent, ‘n read souls. ‘n Frisk’s… the Frisk that freed monsterkind… they were a good soul. the kinda soul that keeps tryin’, even when they mess up. the kinda soul that has** **_good_ ** **intent, even in the worst of circumstances - ‘n that’ll listen ‘n try to help when they can, when they need to.**

Slowly, he fell back into the snow, keeping you snug and warm against his chest as he laid out.

*** … no matter what, they didn’t deserve that fate. i guess i don’t, either, but… i wasn’t goin’ to let the last malice of that ghost damn them by my own choice. so i did what i knew was right.**

You stared at him from your position on his chest - a familiar position to you, after these last few months of you and Sans being a couple, even if your day-to-day hadn’t changed too drastically - and you felt the heat prick at your eyes as his chest rose and fell slowly, shifting you as though you were weightless with it, his arm around you. Your soul was suddenly aching hard in your chest, a resonating thrum growing in it as you stared up at him, feeling almost dizzying in it’s strength as you looked at him-

As you looked at the man you knew to the depths of your soul that you fiercely loved.

Without warning, then, your soul seized in your chest, and your eyes flew wide - simultaneously, Sans made a choked sound as his arm around you tightened, his sockets flying open.

Magic suddenly burst between you both, a blinding swirl of deep blue and brilliant gold, lifting you both off the ground as your senses were overwhelmed, too surprised to even make a sound. A sound like a roar of a storm filled with resonant  _ ringing _ whipped around you as your arms lifted to shield your face -

And suddenly the sound cut off and you landed back on the ground with an unceremonious grunt from both you and the monster you straddled-

Your entire body froze, and you felt the same of the monster below you.

Your knees met snow.

Not more ribcage.

Not even a bare brushing of your toes against the ground as your legs fit around pelvis. 

_ Your knees met snow. _

Your arms pulled away as your eyes shot open.

Below you, half-swimming in the hoodie you had knit for a monster 12-odd feet tall with a horned skull to fit through the neck, was a skeleton monster still - but one with a more human-like skull and precisely zero horns, one about seven feet tall probably. He was lacking a tail too - and absolutely gaping open-jawed between you and the hands he held out of the too-long sleeves of the hoodie-

-of  _ his _ hoodie.

“ _ Sans? _ ” You breathed. 

His jaw worked without sound for a moment, more human-like teeth flashing as he did so, though prominent fangs still lingered-

_ “… angel...?” _

Your eyes widened. His voice had dropped that edge of too-much-magic in it, though it still rolled in that baritone deep way, still  _ him _ , unmistakeably, undeniably-

“did i finally lose the last marble rattling around my skull or am i… normal?” he asked slowly, tentatively, as if he spoke too loud or fast an illusion would shatter.

Your hands finally lowered, resting tentatively on his chest, making him suck in a breath, and your own eyes water unexpectedly.

“I-if ‘normal’ is you looking kind of like a human skeleton but some seven feet tall and with pointy-ass teeth, then… yeah,” you managed to say, your eyes lifting to his, searching his gaze in shock and utter confused awe.

“ _ seven fucking feet-?” _ Sans’ voice was stronger at that, suddenly shifting, pushing upward and sending you off balance - but he caught you easily, his arms just as strong as they had been but much more closely fit to you. His face bowed close to yours as he grunted, seemingly off-kilter with the sudden change in perspective and size.

Sure enough though, judging from the height of his torso from your current position, that was about right-

Your current position, though, was  _ decidedly _ straddling him, your legs having shifted to hook behind his back as he caught you. 

“fuck, you’re right- that’s still taller by a few inches-” he managed to say before his eyelights focused again - this time wholly on your gaze, his low voice cutting off at how he now held you, arching slightly against him, straddled over his lap. 

One of your hands had slowly lifted to his face, hesitating before cupping his cheekbone. A shudder ran up his spine at the contact and he purred - the sound quieter than it always had been, but  _ there _ , half-surprising him even as your heart leapt in your chest at the further confirmation and the familiar sound.

“seems some of the effects of being like that for so long have, uh, lingered,” he said, his voice husky, distracted. He couldn’t look away from you. His cheekbone tilted in that familiar way into your touch. 

“It’s - it’s really still you,” you whispered. 

He nodded as he stared back at you, and you felt your soul begin to thrum bright and hot again. His breath caught in his chest, and his eyelights flickered down to your sternum, and back up to your gaze, and the flush on your cheeks - and so very, very softly, he breathed out an “ _ oh.” _

“O-oh?” you said, your hand smoothing down to his jaw, drawing another clearly pleasured shiver from him.

He was quiet for a moment, his eyelights dilated slightly, and you couldn’t help but feel that he was seeing down to your very soul.

“stars, it really  _ was _ you,” he finally said, his voice raw.

“Me?” Your eyes widened. “You- you think I changed you?”

He shook his head slowly, one arm tightening around you as the other lifted to the line of your jaw. 

“i  _ know _ you did,” he murmured. “you- you can feel it, can’t you…? your soul….?”

Your other hand shifted over your chest, feeling that intense, buzzing, almost-dizzyingly  _ perfect _ hum in your chest. “What is it…?”

He leaned closer to you, his forehead resting against yours, looking at you like nothing else in the world existed.

“our souls are resonating,” he said, his voice awed. “like this, it - it means you lo-” his eyelights shrunk then, as if catching himself. The next moment, he held you closer yet, his sockets filled with a kind of emotion that somehow passed beyond the passion and fondness you had already seen him reveal in the past months. 

His hand cupped your jaw, his mouth barely a breath away from yours as he gazed into your eyes.

“angel… i love you.”

The thrum in your soul rang out like a song.

“Sans-” you gasped, your hands holding him, the words feeling caught, almost, so true they were nearly too hard to say. But in his gaze, in his  _ hold _ , you didn’t doubt him for a second.

“ _ I love you too. _ ”

The next moment your mouths crashed together, both of you moving as one to close that magnetic distance between you. 

It was different kissing him like this, no longer over twice your size, but you still liked it - hell, you  _ loved _ it - his malleable bone moving passionately against your lips, his tongue tracing along the seam of yours before you gasping wantingly into his affection, both of you deepening the kiss as your arms looped around his neck, able to do so for the first time now while kissing him - and he responded by arching your body pleasurably against him, his still-tall and broad frame overwhelming yours perfectly. Straddled over his lap, too, you felt his arousal grow, pressing perfectly against your core, making you moan breathlessly into your kiss as your hips naturally shifted to better catch the length of him-

He growled at your actions, the still-clawed tips of his fingers shifting underneath your jacket to drag heatedly down your back. Your fingers dragged in turn over his vertebrae, your shared passion losing the both of you deeper and deeper in the moment.

Finally you broke free for proper air as he seemed about to flip you to the ground, only to remember where you were. Your foreheads met then instead as your chest heaved against his, a fire behind the starry lights of his sockets that made you want to kiss him all over again-

Instead though, you managed to say, “How, though- how did this…?” 

His dilated eyelights remained on your eyes, clearly struggling to not cave into his instincts. His cheekbones were glowing blue as surely as your face was deeply flushed.

“resonant souls - can be people who’re compatible as friends ‘n reach a point of deep understanding, or it could be souls that’re- well-” his forehead bumped gently against yours, a goofy rise to his heated grin lifting now. “in love,” he said, a softness to his tone that made your heart and soul flutter all over again. “y’know how when i first brought out your soul, you mentioned you could hear me  _ in _ it?” at your recognition his grin warmed further, though a little sheepish. “that’s a, uh, that’s a sign of souls that’re resonatin’ on a deep level, ‘n why i kinda panicked ‘n stopped talkin’ whenever your soul was out for so long, heh. resonant souls can reach better’n any other soul to one another, ‘n between monsters we know they always helped reach monsters that had gone feral, or were in a dangerous level of lost hope, that sorta thing, ‘n the stronger the souls were linked - that is, the closer they had grown lovin’ ‘n carin’ for one another, the better they could-”

His breath caught then, his mind suddenly working through it as he explained the concept to you.

“ _ shit,”  _ he breathed.

Your mind had caught on what his had, your own eyes widening.

“Wait, you’re saying - our souls had started resonating, and the reason I was able to reach yours and- and what,  _ break the spell _ , was because- because I-”

He nodded, looking at you in a mixture of pure awe, brilliant realization, and undeniable love.

Your hand went to your mouth.

“ _ True love?” _

His magic deepened in color on his face, but his grin grew wider yet, his fangs catching the light reflecting from the snow. 

“true fucking love,” he replied.

You were completely red-faced, but your own grin was growing to match his easily.

“... Holy shit.”

“holy fucking shit.”

You snickered at that, the phrasing becoming such a common standard in absurd situations between you two that you loved it - and as he began laughing too, you held him closer, both of you breaking down into the kind of joyous, infectious, utterly overwhelming laughter that comes of a pure kind of happiness that brought tears to your eyes. Your head buried against the crook of his neck, and he held you close, one hand sliding into your hair as his head bowed to the crown of your skull, burying in your locks as you both shook with the swell of emotion-laden joy.

When you finally caught your breath, his deep chuckles settling lingeringly within you, you managed to pull back enough to look up at him, lifting one hand to wipe at your tears before grinning up at him.

He kissed at the tears still lingering by the corner of your eyes, only grinning more at your mild fluster for this, a deep chuckle rolling in him again.

“you really are an angel,” he murmured against your temple. “your soul singin’ out so strong for mine you guided me outta the darkness, raised me right outta perdition by the light of your soul…”

“Sans,” you murmured back, your face turning against his, tenderly kissing the corner of his mouth. “I’m just so happy that-”

Your eyes flew open then, and before he could ask what had happened your hands went to his jaw, your voice urgent-

“Sans, holy-  _ that’s it! _ ”

“i- what?” he said, caught in surprise, confusion clear in his expression as he pulled back enough to look at you properly. “what’s it?”

“ _ Our souls!” _ you said excitedly, the high your soul was already riding on ratcheting up as the idea slammed through you. “If I could reach  _ you _ in your curse or spell or crazy ghost magic or whatever because our souls called out to one another thanks to our strong connection-”

He inhaled sharply.

“ _ we might be able to lock onto them in the Void through it _ ,” he finished. His arm clutched you closer, his eyelights sharp in their focus. “that’s fucking- sweetheart, you  _ genius _ \- we’re close to our siblings, that kind of connection might overwrite the lingering uncertainty, might tether reality enough to keep it from collapsing in on itself-”

His jaw snapped shut as he looked at you, a thousand emotions in his face. 

The next moment he was kissing you again, fierce and passionate, and you responded in kind, dizzied at the sudden welcome onslaught - only when he pulled away a few seconds later did you realize he had risen to his feet, his arms easily shifting you to be carried bridal style. The hoodie hung too long around him but it had hooked over his pelvis, keeping out of the way of his legs and suddenly he took off at a run towards the cabin, holding you close and dear, his eyelights flashing with that particular glint he got in his eye when you were both onto something.

“let’s fucking do this-!”

\---------------------------------------------------

In the end it had taken you nearly a full twelve hours to get everything ready. You had dug up one of the larger hoodies you had salvaged this past year for yourself for him to change into, as well as a pair of sweatpants. The sweatpants ended up having a fitted look and he pushed them up to the top of his calf since they fell too short, and the same had happened with the sleeves of the hoodie being pushed to his elbow, but overall it was good enough - and frankly, he looked  _ damn good _ . 

You had only briefly breaked a couple of times to quickly eat, though one of those times as you both spoke on the steps you were working like a well-oiled machine through, he had looked at you in that way as you elaborated on a thought you had… and the next thing you knew your food had been forgotten and he was kissing you again, your back against the pillows of his nest and his body pressing against yours passionately. 

Several minutes had passed by the time you got a hold of yourselves, tearing yourselves apart enough to get back to the task at hand even though your souls were resonating so perfectly. There was promise in both of your gazes as you pulled away, though - but for now, you had something too important to wait longer to handle - something you had been working intensely on for too long.

Finally, you both stood back, doing a final check on all the systems you had updated for the new input added to the machine. Everything checked out - and you had been cross-checking every step of the way, too, so… it really was time. The small vantablack hole continued rolling in on itself suspended in the center of the large chamber, stable as always.

As one you and Sans both moved to the panel further away, standing behind it and looking towards the machine. His arm looped around your waist securely, drawing you without question firmly against him, and you held him immediately in return. Darker shadows were under both of your eyes for how long you had both been working without proper rest, but it would have been impossible to sleep anyways. As it was, nervous anticipation ran through your veins, making your hands slightly unsteady.

“... this is it,” Sans said, his own voice holding that rough edge, anticipation clear in him as well. He had been working for even longer than you on this, by a lot, even though the stakes were high on both your accounts. His skull turned down to you, his eyelights searching your gaze one more time.

Seeing what apparently he needed to see, then, he bent lower and captured your lips in a kiss, still passionate, but more gentle this time, the heat like a neverending bed of coals as opposed to a blazing fire, stoking a different kind of warmth in you. 

He pulled back slowly. 

You both knew what rode on this - you had essentially already opened a link to the Void, but if your theories were right, then the needed component was the proper  _ connection  _ to the Void, to the  _ something _ within the  _ nothing _ \- in other words, the connection your souls had with your siblings. If it backfired, though, given how vulnerable your souls would be…

You held his gaze in return, nodding up at him.

“Let’s do this.”

He nodded back, a hardened grin rising on his face as he steeled himself. “alright, just keep holding onto me, no matter what. once it gets goin’, i can’t say i expect it’ll feel good - but keep focusin’ on anythin’ and everythin’ to do with your sister. memories, feelin’s, anythin’ that’s a strong tie to her. that ‘n your intent to reach her, bring her back - that oughta do the trick,” he said, his free hand flicking switches into place, booting up the processes and the machine, the hum of it beginning to pick up once again. He then lifted his hand to his own sternum, taking a deep breath. A slight stain of blue magic colored his cheekbones, but he still pulled it out, allowing you to see it properly for the first time-

The sight of it made that brilliant, breath-taking song in your chest pick up again. His soul was a pure white, with the faintest aura of a brilliant deep blue. It seemed to react to the feeling in your chest, twitching towards you - rising the blush on Sans’ cheeks - and pulsing in a way you couldn’t tear your eyes from.

With incredible control and an enormous effort, Sans managed to still his soul from lurching towards you, his hand lifting to your sternum next. He looked at you, his grin lopsided and a little softer for a moment. “no hidin’ that kinda honest soul reaction,” he said, making you grin and blush in return - but then he was moving on and carefully drawing out your own soul, holding it floating above his hand like a priceless treasure. The room began to fade out of your focus, but his words pierced the haze, rolling straight to your soul.

“stay focused, angel. i’m placin’ our souls over the sensor - you just hang onto me, no matter what, ‘n focus on your sister ‘n your connection with her.”

You nodded, doing as he said - maintaining the sense of him, your two souls, and the faintest focus on the machine within your vision and other senses, everything else fading away.

The moment the machine’s true work kicked into gear, you felt it.

Sans dragged you flush against him as you both gasped at the sudden roar of the machine and the inexplicable  _ cold _ feeling washing through your souls. Simultaneously, though, you felt as though a string caught at the center of your soul, taught like a fishing line-

“ _ Sans-! _ ” You gasped.

He grunted in response, his hold on you tight. “that’s the feelin’, angel - grab tight onto that sensation ‘n keep doin’ what you’re doin’-”

You did as he instructed as you watched the golfball-sized vantablack hole suddenly flare out to fill the entirety of the container. The string extending from your soul and into that inky blackness felt hazy and your consciousness couldn’t follow it, but you knew it had somehow  _ connected _ , invisible or no. Fiercely, your soul blazing brighter, you focused on your sister. Every strongest memory of her rose in your mind, from when you were children to the ones far more recently, of laughter and shared pain and fierce connection, the bond you had worked on as sisters over the years stronger for everything you had been through, for your active work and desire to communicate and be there for one another-

Every day of these 15-odd months had been dedicated towards dragging her back from the fate she didn’t deserve, from a terrible accident that never should have happened - you would not let her go, and you  _ would not stop until you had her back-! _

The sound turned deafening then as lights began to flash, your arms clutching tighter at Sans, something now roaring  _ within _ the chamber- 

Suddenly something slammed against it’s inner walls so hard it shook the entire machine, the blackness dripping from like the absence of light turned viscous - but no, you realized, it wasn’t something, it was someone -  _ two _ someones-

You couldn’t hear if the cry had ripped from your throat or not, but either way, your soul pulsed as suddenly the connection slackened and grew stronger, thicker for your proximity - and you saw what could only be your sister, holding tight to a tall skeleton man who held her in return, his sockets wide and his fist slamming against the container, seeming to strain desperately against the blackness behind them.

Your soul nearly slammed back into your chest in shock and surprise, but you saw your sister’s eyes widen then, looking up at you wildly, any words unheard but her head shaking urgently, her mouth forming a single word - ‘ _ No-!’ _

You tore your eyes from her to Sans, neither one of you entirely prepared for the implications of them being in this state with the portal to the VOid clearly still active behind them - he held you off the ground, now, the gravity of the machine nearly too strong to resist even for him. He looked down at you, magic in his eyesockets as he said something, the sound lost to the deafening roar of the split in reality. Still, he seemed to speak again, and you caught the movement of his mouth-

‘ _ trust me, and don’t let go-!’ _

You gripped him as hard as you could in response. 

Magic welled in his body, viscerally felt to you now, and you caught the widening of his own sockets as the magic sparking in his hand suddenly rushed up his arm and into his chest and then in a flash he was suddenly  _ enormous _ \- once more 12 feet tall, the hoodie tearing from him as he reverted back to the form he had with his blaster weapon as his skull- but there was no time to be confused, or to possibly consider lamenting, your grip already barely maintained around him. The magic welled in his mouth, blinding in its concentration as his other hand quickly flew across the panel board, shutting off the activation sequence to connect to the void at the same time he released the built magic in his open maw, the roar of him the only thing that broke over the sheer din of everything else.

In a flash of light too bright to see past, the sound cut off all at once, and you both collapsed to the ground as the gravitational pull of the machine suddenly ceased.

You struggled to your knees immediately despite the weakness in your limbs then, your voice hoarse, frantic - “ _ Sans-! _ ”

He groaned in response, his eyesockets cracking open - he was back to normal again, proper normal, seven feet tall once more, though now shirtless - his ruined hoodie since having fallen to the ground. With a sharp sigh of relief you both suddenly twisted, pulling one another to your feet as you both scrambled to see what had happened, your breath gone -

There, in the smoking remains of the machine, surrounded by the remains of the now shattered chamber, were his brother and your sister, collapsed in the wreckage.

Sans was already pulling you with him, rushing over there as quickly as possible, though you both stopped just short of touching them, terrified of the repercussions, of side effects, barely believing what you saw.

“G,” Sans’ voice called, completely raw, magic beading in his sockets. 

“Sis - oh, god, please-” you said right after him, your hand just shy of her, your heart seizing in your chest. 

Her hair had gone completely white as if the color had been leeched out of it, and strange black marks covered what you could see of her skin - she was still wearing the same tanktop and jeans she had been in the day you both fell down here, though they too had paled out as if the color had been lost. her skin was paled too, but thankfully had some of its normal color still in it - but too pale, even so, like she was sick. “*Please,* please be okay, say something-”

A few seconds later your sister made a soft sound, a groan, shuddering weakly as the arms of Sans’ brother around her tightened slightly and his voice made a low, scratchy growl of a sound. Both you and Sans finally breathed out at their stirring, and carefully Sans reached out, touching his brother’s knee first - and when nothing horrifying happened, Sans’ magic flared to life around the both of them, lifting them from the pile and moving them to his nest of pillows.

Both stirred more properly then as he set them down. By the time your sister was sitting up, Sans’ brother with her, still clutching her - you had pushed forward and thrown your arms around her, and your tears were falling. You felt Sans immediately do the same, dragging his brother into a fierce hug, one of his arms around you too, ending up in a muddled but desperately welcome group hug.

Your sister roused in bursts, first jumping slightly  and then shuddering fiercely as she came properly to, one arm shifting instinctively to hug you back - and then, realizing properly who you were and where she was, a gasp tore from her throat and her arm grabbed tight at you. 

“O-oh my gods, it’s- it’s really you,” she said, her voice sounding just as raw, and you felt tears hit your shoulder where her face buried. “F-fuck, it’s - you did it sis, *you did it*-”

She began sobbing then, clutching you closer. Just as close you heard Sans gasp out “*G* - bro, you’re - you’re back, you’re safe - you’re free-”

“*Thank you*,” was the broken gasp of his brother, suddenly overcome with just as much emotion. His voice had a strange staticy sound to it, like an old warm tuner radio, but any further thought was lost as an immeasurable amount of time passed as you clung to one another, desperately grounding yourselves as your tears fell.

Finally you felt your sister pull back just enough to catch your gaze, her hand clutching at your shoulder. “How did you manage figure it out?” She said, looking up at you and then to Sans. You noticed then that the necklace you had sent into the Void was looped around her neck, hanging low, both the crystal and the claw intact.

Sans laughed, the sound almost lost, something far deeper than happiness and pure lost emotion in his voice as he glanced to your sister and back to his brother. “it was all her - savin’ me as she has every step of the way, it seems.”

His brother’s eyesockets widened. You properly noticed now that he had a deep split running up from his right eyesocket and to the back of his skull, while another split ran from his lower left to his mouth. He too had sharp canines, though not as much so as Sans’ - but his sudden quirked grin was so alike their relation would be impossible to miss. 

“Dearheart, I do believe you won our bet,” he said, that quality of radio static remaining in his tone - and you realized he had glanced back to your sister at that, a knowing spark to his eyelights, a certain way he looked at her incredibly familiar-

“Oh my god,” you and your sister both said at the same time. You looked at each other and suddenly you were laughing, a new rush of disbelief and joy and incredulousness clear in you both for your mirrored mannerisms and the realization.

“You  _ did _ fall for him, I knew it, I knew you would-!” she said, grinning at you as she caught her breath. Her gaze went to the skeleton still holding her by one arm, a clear fondness and mischievous sparkle in her own exhausted gaze. “I’m gonna collect later, G,” she said, her brow quirking, and he chuckled, his gaze narrowing.

“I shall hold you to that.”

Sans’ hand lifted from his brother to hit his forehead, his gaze matching with your in amusement, disbelief, relief, and more. “G, you son of a - you get  _ one _ woman in there, and you go and woo the hell outta her?” 

Your sister snickered at this, but G rolled his eyes with a deeply purple flush rose to his own cheekbones. “You’re certainly one to talk, Sans-”

Sans was blushing now, though he tried to play it off. “Hey, that’s different, we’re right for - we resonated dammit, we’re soulma-” His sockets widened, his blush deepened, and his eyelights flashed to you.

Your own blush had picked up, too easily picking up on the last piece of that word.

“Does… ‘soulmate’ mean something specific by any chance in monster culture?” You managed to say, trying desperately now to  _ not _ glance at your sister.

It was Sans’ brother who spoke before Sans could, though, drawing your gaze. “Indeed it does - soulmates have a different connotation than apparently popular human culture designates these days. A soulmate is someone who has resonated with someone strongly, down to the depths of their being, their compatibility and also earned trust and unshaking love in one another so complete that their souls sing for one another. Soulmates almost always end up properly as claimed mates,” he explained easily with a grin, simple and clear and as if he was simply talking about the reason ice melted in an oven. The slight quirk to his grin, though- you had a feeling he knew precisely what he was doing. “Ah, my name is Gaster, by the way, my dear - Dr. W.D. Gaster, though you may of course call me G - any friend of mine may, and I dare say I hope we will be.”

You reeled slightly from the mild flood of information, but introduced yourself in turn, before your gaze slanted to your sister. “Hold up, though, wait - how’s he know so much about pop culture on soulmates? Don’t tell me-”

She met your gaze, her face utterly betraying her in how red it had turned, but she just grinned at you with a sheepish but unashamed laugh - one that warmed you to your soul, and you didn’t even care to fight the tears that came to your eyes again.

“You- you-” Your hand shifted, and you flicked her square in the middle of her forehead, and dragged her against you again as she tried to slap her hand to cover the spot. “You  _ absolute idiot, _ ” you finished, your voice completely exasperated and utterly relieved.

Her arms circled you immediately, dragging you close despite the slight red mark on her forehead now, a wet laugh coming from her. “Love you too, big sis…”

\------------------------------------

Another hour at least had passed as they got their bearing and you caught up on the bare minimum of information, on what had happened and how much time had passed, both of them seeming understandably deeply disoriented on that front - when you said it had been about 15 months, they exchanged a look more serious than most of their other ones so far, and your sister seemed to smile a sort of resigned smile when she noticed you caught the look.

She sighed, rubbing lightly at her neck, looking slightly reluctant to tell you this. “... We can get into the headache-inducing details of how it works later, but, uh… time doesn’t really flow  _ normally _ in the Void, it turns out,” she explained. 

“What do you mean?” You leaned forward slightly, your brow furrowing, sat beween Sans’ legs turned towards her as she leaned against Gaster. Sans leaned in too, clearly curious.

She grimaced lightly, glancing up to Gaster. Her other hand was clasped with his, playing with the fused digits of his bones - he seemed slightly more fused than Sans was, the connections a little smoothe between his bones. He also had a perfect circle pierced through either palm, rimmed in vantablack - her own marks over her skin, slashed like scars from countless fights, had a similar vantablack appearance… Though her skin had returned to her normal color, at least, even if her hair remained white. 

“Well… basically, if time flows more or less in a line  _ normally _ in reality, barring any time manipulation... time in the Void is more like… a toddler’s scribble in crayon?” She said. “Loops, and weird joints, and crossovers with reality proper-” She gestured vaguely with her hand, trying to convey how convoluted it is.

Gaster spoke up then, his thumb tracing over her knuckles. “Any point where ‘time’ in the Void crosses with reality - we could catch the slightest glimpse of it. Your sister compared it to like looking into a badly staticked VR headset,” he elaborated. She nodded at this. “Everything looks strangely fuzzy and a bit greyed out, and moves so slow you can barely tell that things are supposed to be moving.”

Your swore under your breath at the same time as Sans.

“you’re sayin’... you lived a hell of a lot more time in there than passed out here…?” His voice was tight - guilt eating at him, you knew, though he tried to hide it.

Gaster smiled ruefully. “... Yes, it would seem so. Oddly enough, the Void though sort of… becomes a part of your existence at a core level - or perhaps just rubs off on you if you spend long enough in there…” His eyelights went to your sister’s hair and the marks on her, and you realized that must be the source of the odd effect to his voice as well. “Time stops flowing normally for you, too, so…  _ physically _ , we both seem to show next to no signs of ageing in that respect.”

“How much time  _ did _ pass for you? At least the past - well, 15 months for us?” You ventured then, dreading the answer, but needing to know.

Your sister cocked her head slightly, glancing to the side. “Well, it’s hard for us to pin down, but from what we could narrow down based on crossing points with reality…” She looked back up at you with a soft smile, no blame or upset in it for you. “... at least six years.”

“ _ WHAT.” _

She laughed sheepishly. “Yeah, though it’s a bit of a rough estimate. Apparently the Void also doesn’t have you needing sleep or food or anything else since there’s no true time  _ or _ defined sense-making space, so…”

The conversation continued like that, you and Sans probing for questions that didn’t delve quite  _ too _ deep as you came to realize that it had been more than idle waiting they had done in there. Your sister apparently sported those scars for a reason - the Void was filled with faceless, shapeless  _ things _ , beings of pure timeless  _ chaos _ , seeking only to maintain the entropy of the Void. Something,  _ two _ somethings with as much order as a physical body or magic or a  _ soul _ was like a beacon in the vast nothingness, and they had countless run-ins with them as they moved from one nowhere to another -they both looked so achingly tired at this track of conversation though that unanimously you and Sans both dropped it for now, the information not so pressing as to be unable to wait.

Finally, both of them simply… fell backwards, dead asleep.

Apparently, it was the first time either of them had slept since entering the Void. Periods of rest had existed, but… sleep never came. Not in the Void.

You curled up against Sans as they drifted off, remaining close to your sister, literally within arm’s reach as you finally broke your stare away from them to look up at him. 

He was already gazing down at you, his arms holding you close as he too fell back against the pillows and blankets. 

“... I… I don’t know how to fix this,” you murmured, knowing even as you said it that there was no fixing it.

He shook his head, seeing the knowledge in your eyes, drawing you down to rest against him, laying over his chest with his arms around you, propped up slightly by the natural incline.

“the best either of us are gonna be able to do is just… be there for ‘em,” he murmured in return. His hand slid up your back to once again card through your hair, massaging gentle circles in your scalp. “at least… at least after your sister got there, bad as it was, they had each other,” he said, his soul clearly torn on that as the mixed blessing and curse it was.

You nodded though, knowing what he meant. As much as you wish neither of them had been in there - let alone for however god-knows-how-many years Gaster experienced in there… at least they had someone who understood - and hell, from the way they held each other, even in sleep…? They really were that kind of tightly knit. 

You cuddled closer to Sans, and he returned the affection and needed closeness, tucking your head under his chin and drawing one of his blankets over the both of you, his magic flickering briefly to life to do the same with a blanket for them.

You were quiet for a long time, but finally you said, “... Guess you still have access to the  _ big guns _ ,” you joked quietly, looking up at him with a half-grin.

He snorted, a chuckle following as he looked down at you with a too-pleased grin. “seems like. rather than being able to once again call out my blasters, i just… shift back into blaster-me,” he said with a wry twist to his look. It turned mischievous then, though, and he waggled his brow at you. “so if you ever want a ticket to the gunshow, angel…”

You laughed into his chest, muffling the sound at his flirting. When you looked back up, you managed to say, “Well, I like you  _ any _ way you come, so that’s up to you.”

He blushed slightly, a warm hum in his chest - but then his brow lifted, a shit-eating devilish grin sliding upwards. “you like me any way i come, hmmm?  _ do tell _ …”

You smacked at his chest, but couldn’t mask the flushed sparkle to your eye as you tried not to laugh. You failed miserably, your head once more falling to his chest, and he laughed quietly too, shifting you both to  roll to the side so you rested against him and close to your sister as he pressed playful kisses to your face, making you struggle more to not laugh and wake either of your siblings, returning his kisses to give him similar trouble, but failing miserably when he seemed a little too delighted at his plan going apparently according to plan.

He relented at last though, and finally you began to fall quiet, the exhaustion clearly taking its toll on you both as well. You were reluctant to sleep, but couldn’t help but hope this really wasn’t just a dream. 

“... Sans,” you ventured softly.

“mmmm,” he replied vaguely, his head nuzzling gently against yours as you pressed closer to him.

“... Do you think that the barrier broke when you changed back…?”

He was quiet for a long time.

“... that’s what i’m hopin’.”

“... Me too. We can go check it out once we all wake up.”

None of you would want to be out of the same room with you more than absolutely necessary for at least a couple days, and close by frequently far, far longer than that. You were also fairly certain neither you nor Sans could quite bear to check out barrier alone. 

His arms kept you tucked perfectly close to him, your bodies a perfect fit against one another despite his size, and in this you drifted off to his soft murmuring.

“we’ll take care of it, no matter what, angel. i’ll make sure you see the open skies again - that we can all see 'em  together .”

\--------------------------------------------------------------------------

The next day, you fished out a new hoodie out for Sans, and another one for your sister given the fall month it would be if you  _ could  _ walk out - and thankfully Gaster, even taller than Sans by several inches already wore a thick, plush turtleneck sweater. Not wanting to delay longer, you all immediately began the trek through the Underground. Sans wasn’t quite willing to risk teleporting yet given the odd tweaks already found in his magic, and you couldn't blame him. 

Your sister’s first delighted love of Waterfall and then quickly comically horrified reaction to Hotland was almost worth the unbearable heat.

Almost.

As you made your way through what had apparently been the King’s house, the nerves finally became too hard to push away anymore. Your hand was intertwined with Sans’, your own jacket since donned. Your sister walked hand in hand with G in turn - various conversations both light and heavier had flowed between all of you, and they had since fully heard the implications of the barrier.

“... I hope they  _ are _ able to remember us,” your sister murmured to your side. “Maybe they just need a trigger to jumpstart it?”

“I hope it’s that simple,” you said quietly.

Sans’ thumb smoothed over your knuckles, and you squeezed his hand gratefully in return.

When you walked into the room that had Sans’ and Gaster’s shoulders go matchingly tense, you knew it was time to see for certain, and you steeled yourself for the worst-

“I TOLD YOU! IT’S THEM - IT’S- IT’S MY  _ BROTHERS!” _

A red-scarfed blur suddenly slammed into the four of you as you entered the final passage where the barrier would have been, dragging a near-unified grunt from you all as none other than the Great Papyrus himself tackled you all to the ground, tears falling from his sockets.

“Holy shit, Paps- thank Asgore your hunch was right- Alphys- Alph, babe, quick, call Grillby and Muffet, we’re gonna need them after all-” 

“SANS - G - HUMANS-”

He seemed unable to speak and simply tried to hug all of you at once, a sob breaking free in joy from him while you realized magic sweat covered his skull and his clothes were dusty as if he had been hiking urgently for hours. Undyne came to a pounding stop behind him, wetness brimming at her eye too, her voice choked in a way more emotional than you’d ever heard her.

“What the fuck happened?!” She still managed. In the background you could her Alphys standing just outside the edge of the cave as Papyrus struggled to his feet again, managing somehow to drag all of you with him so he and Undyne could help all of you forward, have dragging, half properly guiding. “All of a sudden this morning we all remember that  _ you _ went missing, and weren’t dead after all-” she jabbed her finger at you, “that  _ you two _ fucking  _ existed _ -” two fingers to Gaster and your sister, “and that  _ you _ fucking never got out of the Underground for a reason no one knew- we  _ lost our goddamn shit, you punks!” _

You could see the glow of a sunset from outside the last length of the cave’s edge now.

“... that’s a long story,” Sans managed to say roughly, one arm lifting to remain looped over Papyrus’ shoulder, seeming lost to further words as he clutched at his brother, not having let go since Papyrus tackled the four of you. 

“WE’VE GOT TIME!!” Papyrus insisted, his bright voice still choked, his tears not slowing. His arm was around Sans, his other dragging Gaster closer as you finally broke free of the Underground, fresh air hitting your lungs for the first time in far too long. 

The sun was setting in the west behind the city, the ocean sparkling in the distance.

Sans’ hand gripped yours - and as you looked up at him, you saw a fresh wave of magic tears falling down his face, and you turned to hug him fiercely, dragging your sister and thus Gaster with you. Papyrus welcomed the group hug, and you felt Undyne join on the other side, and Alphys voice came close and you felt the slightest jostle as she joined in too, her voice lost then under the way Sans murmured in that way that struck you down to the depths of your soul, his hand never once leaving yours, his words making a wet laugh pull out of you as you embraced the monster you had fallen so deeply in love with, and as he held you close in return, surrounded by your closest friends and family.

“... holy shit, angel.”

“Holy fucking shit, Sans.”

 

**Notes for the Chapter:**

> and so at last it ends! what started as a birthday gift has now concluded as a christmas present to my kickass sister joliemariella - and i hope anyone else who has read this enjoyed it as well-! i'd love to hear what you think of this little saga (turned far larger than originally intended because i have no self control. each 'date' listed was meant originally to only be about a thousand words.... _pffffff._ )
> 
> to those 15 comments that have been left betweeen when i posted the first chapter in July to when i'm posting this final chapter now in December, i just want to let you know that i adore you and eternally give you the highest of internet fives.
> 
> merry gyftmas, sis, 'n on to all the rest of you cuties as well >:D <3

**Author's Note:**

> ... what could go wrong?  <3


End file.
